<?xml version="1.0" encoding="UTF-8"?>

<!--XBRL Document Created with Wdesk from Workiva-->
<!--Copyright 2021 Workiva-->
<!--r:b062a29f-b1df-4acd-8142-e43187670eb6,g:0d4da5da-795c-4ced-82bf-9f98f7e76b59-->
<link:linkbase xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/all" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#hypercube-dimension"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-default"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-domain"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/domain-member" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#domain-member"/>
  <link:roleRef roleURI="http://wabtec.com/role/COVERPAGE" xlink:type="simple" xlink:href="wab-20201231.xsd#COVERPAGE"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/COVERPAGE" xlink:type="extended" id="i81fe1e17bfb3451aae994c90dcea7ef2_COVERPAGE"/>
  <link:roleRef roleURI="http://wabtec.com/role/CONSOLIDATEDBALANCESHEETS" xlink:type="simple" xlink:href="wab-20201231.xsd#CONSOLIDATEDBALANCESHEETS"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/CONSOLIDATEDBALANCESHEETS" xlink:type="extended" id="i775c37dbc91e4d8cb87724c100e867a7_CONSOLIDATEDBALANCESHEETS"/>
  <link:roleRef roleURI="http://wabtec.com/role/CONSOLIDATEDBALANCESHEETSParenthetical" xlink:type="simple" xlink:href="wab-20201231.xsd#CONSOLIDATEDBALANCESHEETSParenthetical"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/CONSOLIDATEDBALANCESHEETSParenthetical" xlink:type="extended" id="i05b0957d8ffe40efb729d358ce4bb1f4_CONSOLIDATEDBALANCESHEETSParenthetical"/>
  <link:roleRef roleURI="http://wabtec.com/role/CONSOLIDATEDSTATEMENTSOFINCOME" xlink:type="simple" xlink:href="wab-20201231.xsd#CONSOLIDATEDSTATEMENTSOFINCOME"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/CONSOLIDATEDSTATEMENTSOFINCOME" xlink:type="extended" id="i8975a4bd6b2e4fd6a68d3fbc1cc9b1ea_CONSOLIDATEDSTATEMENTSOFINCOME">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_8d2d1591-1681-4279-b8e0-854416f067cf" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenuesAbstract_87abf4d7-55b5-4a83-b68c-7189be0b8b4c" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevenuesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_8d2d1591-1681-4279-b8e0-854416f067cf" xlink:to="loc_us-gaap_RevenuesAbstract_87abf4d7-55b5-4a83-b68c-7189be0b8b4c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_ac2445b5-bdf0-4204-a176-703960b8aee6" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesAbstract_87abf4d7-55b5-4a83-b68c-7189be0b8b4c" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_ac2445b5-bdf0-4204-a176-703960b8aee6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfRevenueAbstract_b7d35020-b43e-4126-b689-1b2fa5df7143" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CostOfRevenueAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_8d2d1591-1681-4279-b8e0-854416f067cf" xlink:to="loc_us-gaap_CostOfRevenueAbstract_b7d35020-b43e-4126-b689-1b2fa5df7143" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfGoodsAndServicesSold_08ef7df4-374d-45db-acdf-4ce99f9c67f1" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CostOfGoodsAndServicesSold"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CostOfRevenueAbstract_b7d35020-b43e-4126-b689-1b2fa5df7143" xlink:to="loc_us-gaap_CostOfGoodsAndServicesSold_08ef7df4-374d-45db-acdf-4ce99f9c67f1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GrossProfit_d6b4db0b-d8f2-4f1d-b1a6-1668b2597134" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_GrossProfit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_8d2d1591-1681-4279-b8e0-854416f067cf" xlink:to="loc_us-gaap_GrossProfit_d6b4db0b-d8f2-4f1d-b1a6-1668b2597134" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingExpensesAbstract_a8f98f9c-3630-4c0f-91e5-1e48521cd248" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OperatingExpensesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_8d2d1591-1681-4279-b8e0-854416f067cf" xlink:to="loc_us-gaap_OperatingExpensesAbstract_a8f98f9c-3630-4c0f-91e5-1e48521cd248" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SellingGeneralAndAdministrativeExpense_5b2b42d4-f1b6-48ca-9c85-9a15ce0a46d5" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SellingGeneralAndAdministrativeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_a8f98f9c-3630-4c0f-91e5-1e48521cd248" xlink:to="loc_us-gaap_SellingGeneralAndAdministrativeExpense_5b2b42d4-f1b6-48ca-9c85-9a15ce0a46d5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResearchAndDevelopmentExpense_cb1cdd4e-fbe9-4cad-b03c-fea0c4d23645" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ResearchAndDevelopmentExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_a8f98f9c-3630-4c0f-91e5-1e48521cd248" xlink:to="loc_us-gaap_ResearchAndDevelopmentExpense_cb1cdd4e-fbe9-4cad-b03c-fea0c4d23645" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfIntangibleAssets_1e3c13b4-14c4-43ce-b4cf-a033eae2eec8" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AmortizationOfIntangibleAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_a8f98f9c-3630-4c0f-91e5-1e48521cd248" xlink:to="loc_us-gaap_AmortizationOfIntangibleAssets_1e3c13b4-14c4-43ce-b4cf-a033eae2eec8" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingExpenses_c5e169a0-bdf2-4726-a605-2c2522a218fd" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OperatingExpenses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_a8f98f9c-3630-4c0f-91e5-1e48521cd248" xlink:to="loc_us-gaap_OperatingExpenses_c5e169a0-bdf2-4726-a605-2c2522a218fd" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingIncomeLoss_ae5bab3e-01dd-4e37-87b7-0de7418797fc" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OperatingIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_8d2d1591-1681-4279-b8e0-854416f067cf" xlink:to="loc_us-gaap_OperatingIncomeLoss_ae5bab3e-01dd-4e37-87b7-0de7418797fc" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonoperatingIncomeExpenseAbstract_cc7f3387-5fc3-41aa-bd08-35f725a08470" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NonoperatingIncomeExpenseAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_8d2d1591-1681-4279-b8e0-854416f067cf" xlink:to="loc_us-gaap_NonoperatingIncomeExpenseAbstract_cc7f3387-5fc3-41aa-bd08-35f725a08470" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeExpenseNet_180837fa-6964-45f2-ba5e-83bb4e86d08d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_InterestIncomeExpenseNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NonoperatingIncomeExpenseAbstract_cc7f3387-5fc3-41aa-bd08-35f725a08470" xlink:to="loc_us-gaap_InterestIncomeExpenseNet_180837fa-6964-45f2-ba5e-83bb4e86d08d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonoperatingIncomeExpense_2460b60b-9f5c-4443-82a8-8b503539bdca" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NonoperatingIncomeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NonoperatingIncomeExpenseAbstract_cc7f3387-5fc3-41aa-bd08-35f725a08470" xlink:to="loc_us-gaap_NonoperatingIncomeExpense_2460b60b-9f5c-4443-82a8-8b503539bdca" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_cf38e415-0546-4b1d-983b-0ab3a7b17643" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_8d2d1591-1681-4279-b8e0-854416f067cf" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_cf38e415-0546-4b1d-983b-0ab3a7b17643" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_764cfd98-76dd-4bd1-ac2e-24f5586cbcaf" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeTaxExpenseBenefit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_8d2d1591-1681-4279-b8e0-854416f067cf" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_764cfd98-76dd-4bd1-ac2e-24f5586cbcaf" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfitLoss_d92dd1ac-8c37-48b4-bdec-f654e5b6f774" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ProfitLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_8d2d1591-1681-4279-b8e0-854416f067cf" xlink:to="loc_us-gaap_ProfitLoss_d92dd1ac-8c37-48b4-bdec-f654e5b6f774" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_17003dbf-770d-4fc8-ae81-a02b1be9fe49" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NetIncomeLossAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_8d2d1591-1681-4279-b8e0-854416f067cf" xlink:to="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_17003dbf-770d-4fc8-ae81-a02b1be9fe49" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_3710d053-20f9-487f-8154-6d6ad48c69fa" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_8d2d1591-1681-4279-b8e0-854416f067cf" xlink:to="loc_us-gaap_NetIncomeLoss_3710d053-20f9-487f-8154-6d6ad48c69fa" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareAbstract_20bf3a1a-ce2b-48a7-bae7-2afc2a7720b7" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EarningsPerShareAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_8d2d1591-1681-4279-b8e0-854416f067cf" xlink:to="loc_us-gaap_EarningsPerShareAbstract_20bf3a1a-ce2b-48a7-bae7-2afc2a7720b7" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareBasicAbstract_fbe2f0f0-7970-4521-ba33-e59dc05ec87d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EarningsPerShareBasicAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareAbstract_20bf3a1a-ce2b-48a7-bae7-2afc2a7720b7" xlink:to="loc_us-gaap_EarningsPerShareBasicAbstract_fbe2f0f0-7970-4521-ba33-e59dc05ec87d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareBasic_cf598ed6-4658-4a8e-b621-461540833eaf" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EarningsPerShareBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareBasicAbstract_fbe2f0f0-7970-4521-ba33-e59dc05ec87d" xlink:to="loc_us-gaap_EarningsPerShareBasic_cf598ed6-4658-4a8e-b621-461540833eaf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareDilutedAbstract_83f56f01-c32d-46c8-891d-ed6dc552372a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EarningsPerShareDilutedAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareAbstract_20bf3a1a-ce2b-48a7-bae7-2afc2a7720b7" xlink:to="loc_us-gaap_EarningsPerShareDilutedAbstract_83f56f01-c32d-46c8-891d-ed6dc552372a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareDiluted_2d496189-e501-4c6c-b14a-eac202a0cf1e" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EarningsPerShareDiluted"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareDilutedAbstract_83f56f01-c32d-46c8-891d-ed6dc552372a" xlink:to="loc_us-gaap_EarningsPerShareDiluted_2d496189-e501-4c6c-b14a-eac202a0cf1e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_d2232a48-11e1-477c-9c4f-8bdb3098f240" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_8d2d1591-1681-4279-b8e0-854416f067cf" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_d2232a48-11e1-477c-9c4f-8bdb3098f240" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_763ae1d2-bab3-4b77-83fb-cb1fb3ad1346" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_d2232a48-11e1-477c-9c4f-8bdb3098f240" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_763ae1d2-bab3-4b77-83fb-cb1fb3ad1346" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_efe0d25c-454f-4657-a274-cf155520f9ce" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_d2232a48-11e1-477c-9c4f-8bdb3098f240" xlink:to="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_efe0d25c-454f-4657-a274-cf155520f9ce" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_9bad0c59-d73a-4776-8b81-3198127636a6" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_8d2d1591-1681-4279-b8e0-854416f067cf" xlink:to="loc_us-gaap_StatementTable_9bad0c59-d73a-4776-8b81-3198127636a6" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_0e0a57ef-fb16-4d59-9492-93970a4aa4a2" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_9bad0c59-d73a-4776-8b81-3198127636a6" xlink:to="loc_srt_ProductOrServiceAxis_0e0a57ef-fb16-4d59-9492-93970a4aa4a2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_0e0a57ef-fb16-4d59-9492-93970a4aa4a2_default" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_0e0a57ef-fb16-4d59-9492-93970a4aa4a2" xlink:to="loc_srt_ProductsAndServicesDomain_0e0a57ef-fb16-4d59-9492-93970a4aa4a2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_781f94a4-fce0-4afa-9351-637eb1e9353c" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_0e0a57ef-fb16-4d59-9492-93970a4aa4a2" xlink:to="loc_srt_ProductsAndServicesDomain_781f94a4-fce0-4afa-9351-637eb1e9353c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProductMember_a17f9afd-e407-43af-82e1-411c5e9f8cdf" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ProductMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_781f94a4-fce0-4afa-9351-637eb1e9353c" xlink:to="loc_us-gaap_ProductMember_a17f9afd-e407-43af-82e1-411c5e9f8cdf" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ServiceMember_8b5b9318-cbe2-4a63-bc3a-6cb7d029308b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ServiceMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_781f94a4-fce0-4afa-9351-637eb1e9353c" xlink:to="loc_us-gaap_ServiceMember_8b5b9318-cbe2-4a63-bc3a-6cb7d029308b" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/CONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOME" xlink:type="simple" xlink:href="wab-20201231.xsd#CONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOME"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/CONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOME" xlink:type="extended" id="id8d1ce0c7f0e438484808b2ef4bf8d69_CONSOLIDATEDSTATEMENTSOFCOMPREHENSIVEINCOME"/>
  <link:roleRef roleURI="http://wabtec.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS" xlink:type="simple" xlink:href="wab-20201231.xsd#CONSOLIDATEDSTATEMENTSOFCASHFLOWS"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/CONSOLIDATEDSTATEMENTSOFCASHFLOWS" xlink:type="extended" id="i4c84c51ddb6e485da0bb99223797cd74_CONSOLIDATEDSTATEMENTSOFCASHFLOWS"/>
  <link:roleRef roleURI="http://wabtec.com/role/CONSOLIDATEDSTATEMENTSOFSHAREHOLDERSEQUITY" xlink:type="simple" xlink:href="wab-20201231.xsd#CONSOLIDATEDSTATEMENTSOFSHAREHOLDERSEQUITY"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/CONSOLIDATEDSTATEMENTSOFSHAREHOLDERSEQUITY" xlink:type="extended" id="i0068c7dabcb54c82b0cb9ce0c8c9b8d7_CONSOLIDATEDSTATEMENTSOFSHAREHOLDERSEQUITY">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_f32575b9-028f-4a70-a684-0f7d8813ea45" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_aa0a1382-a5be-493d-9041-dd8cbeb2ed85" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncreaseDecreaseInStockholdersEquityRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_f32575b9-028f-4a70-a684-0f7d8813ea45" xlink:to="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_aa0a1382-a5be-493d-9041-dd8cbeb2ed85" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharesIssued_9846133f-9974-4031-96f5-a95f0410122c" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_aa0a1382-a5be-493d-9041-dd8cbeb2ed85" xlink:to="loc_us-gaap_SharesIssued_9846133f-9974-4031-96f5-a95f0410122c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_dfe136bb-0bec-44c3-9a0f-7481edbef636" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_aa0a1382-a5be-493d-9041-dd8cbeb2ed85" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_dfe136bb-0bec-44c3-9a0f-7481edbef636" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsCash_56eaaf20-66ec-4b53-b107-9839b1254fad" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DividendsCash"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_aa0a1382-a5be-493d-9041-dd8cbeb2ed85" xlink:to="loc_us-gaap_DividendsCash_56eaaf20-66ec-4b53-b107-9839b1254fad" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsCommonStockCash_56b3c777-d231-4774-9ed4-c33105184766" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DividendsCommonStockCash"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_aa0a1382-a5be-493d-9041-dd8cbeb2ed85" xlink:to="loc_us-gaap_DividendsCommonStockCash_56b3c777-d231-4774-9ed4-c33105184766" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_StockGrantedExercisedAndCancelledForVariousEquityInstruments_60c653f8-59c5-4e50-9e31-41959f7d1094" xlink:href="wab-20201231.xsd#wab_StockGrantedExercisedAndCancelledForVariousEquityInstruments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_aa0a1382-a5be-493d-9041-dd8cbeb2ed85" xlink:to="loc_wab_StockGrantedExercisedAndCancelledForVariousEquityInstruments_60c653f8-59c5-4e50-9e31-41959f7d1094" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised_3ffd3779-ca51-4e3c-9802-cbec64381d92" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_aa0a1382-a5be-493d-9041-dd8cbeb2ed85" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised_3ffd3779-ca51-4e3c-9802-cbec64381d92" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_062dea43-fab6-4d90-bec9-013fa16e72b9" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_aa0a1382-a5be-493d-9041-dd8cbeb2ed85" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_062dea43-fab6-4d90-bec9-013fa16e72b9" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfitLoss_40dc2e7e-6862-469e-9706-9d6aa292d6c5" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ProfitLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_aa0a1382-a5be-493d-9041-dd8cbeb2ed85" xlink:to="loc_us-gaap_ProfitLoss_40dc2e7e-6862-469e-9706-9d6aa292d6c5" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax_0ea214f9-5705-4536-b377-08fb2e364895" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_aa0a1382-a5be-493d-9041-dd8cbeb2ed85" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax_0ea214f9-5705-4536-b377-08fb2e364895" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MinorityInterestDecreaseFromRedemptions_c8cff8a3-9131-496b-8cce-04b3f9ae204c" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_MinorityInterestDecreaseFromRedemptions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_aa0a1382-a5be-493d-9041-dd8cbeb2ed85" xlink:to="loc_us-gaap_MinorityInterestDecreaseFromRedemptions_c8cff8a3-9131-496b-8cce-04b3f9ae204c" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesAcquisitions_414f7a13-68b1-4fef-be70-51d4ee0371d6" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesAcquisitions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_aa0a1382-a5be-493d-9041-dd8cbeb2ed85" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesAcquisitions_414f7a13-68b1-4fef-be70-51d4ee0371d6" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueAcquisitions_cff56801-948b-463b-a9c4-9d2be2addf97" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueAcquisitions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_aa0a1382-a5be-493d-9041-dd8cbeb2ed85" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueAcquisitions_cff56801-948b-463b-a9c4-9d2be2addf97" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockSharesAcquired_6a2e8f4b-1ab7-475f-b30f-8ba7afb2d4cd" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TreasuryStockSharesAcquired"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_aa0a1382-a5be-493d-9041-dd8cbeb2ed85" xlink:to="loc_us-gaap_TreasuryStockSharesAcquired_6a2e8f4b-1ab7-475f-b30f-8ba7afb2d4cd" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockValueAcquiredCostMethod_160422b6-ab7c-4781-80c3-503f3a3aaece" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TreasuryStockValueAcquiredCostMethod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_aa0a1382-a5be-493d-9041-dd8cbeb2ed85" xlink:to="loc_us-gaap_TreasuryStockValueAcquiredCostMethod_160422b6-ab7c-4781-80c3-503f3a3aaece" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityOther_36f9aab1-43ff-4644-83f4-5a8690315662" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockholdersEquityOther"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_aa0a1382-a5be-493d-9041-dd8cbeb2ed85" xlink:to="loc_us-gaap_StockholdersEquityOther_36f9aab1-43ff-4644-83f4-5a8690315662" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharesIssued_9a14f458-880c-4bf2-9af8-61f15c68a2b3" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SharesIssued"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_6d66d244-c461-4aa2-9e7a-c1fff624daaf" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_70e0f2fd-49ae-405e-92e6-09c04fe2541e" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_f32575b9-028f-4a70-a684-0f7d8813ea45" xlink:to="loc_us-gaap_StatementTable_70e0f2fd-49ae-405e-92e6-09c04fe2541e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_39e52de3-b6b1-46ec-aa80-a556f37fe788" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_70e0f2fd-49ae-405e-92e6-09c04fe2541e" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_39e52de3-b6b1-46ec-aa80-a556f37fe788" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_39e52de3-b6b1-46ec-aa80-a556f37fe788_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_39e52de3-b6b1-46ec-aa80-a556f37fe788" xlink:to="loc_us-gaap_EquityComponentDomain_39e52de3-b6b1-46ec-aa80-a556f37fe788_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_9d0aea86-77af-4623-bfe5-b85cc2dd4585" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_39e52de3-b6b1-46ec-aa80-a556f37fe788" xlink:to="loc_us-gaap_EquityComponentDomain_9d0aea86-77af-4623-bfe5-b85cc2dd4585" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_973a405d-9cdb-4134-91de-e9194f083858" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_9d0aea86-77af-4623-bfe5-b85cc2dd4585" xlink:to="loc_us-gaap_CommonStockMember_973a405d-9cdb-4134-91de-e9194f083858" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalMember_e0e333cc-a141-4580-a2be-f0b3945c5aea" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AdditionalPaidInCapitalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_9d0aea86-77af-4623-bfe5-b85cc2dd4585" xlink:to="loc_us-gaap_AdditionalPaidInCapitalMember_e0e333cc-a141-4580-a2be-f0b3945c5aea" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockMember_843f2477-e470-4181-b0fc-4fde0ee003b5" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TreasuryStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_9d0aea86-77af-4623-bfe5-b85cc2dd4585" xlink:to="loc_us-gaap_TreasuryStockMember_843f2477-e470-4181-b0fc-4fde0ee003b5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsMember_a50053ce-0cfd-4c9b-8313-f8dacd96b352" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetainedEarningsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_9d0aea86-77af-4623-bfe5-b85cc2dd4585" xlink:to="loc_us-gaap_RetainedEarningsMember_a50053ce-0cfd-4c9b-8313-f8dacd96b352" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_0a9a2ba4-2f61-48a3-aeaa-50456d7602f5" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_9d0aea86-77af-4623-bfe5-b85cc2dd4585" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_0a9a2ba4-2f61-48a3-aeaa-50456d7602f5" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoncontrollingInterestMember_03133217-6eae-43f4-b601-e933f47ff742" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NoncontrollingInterestMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_9d0aea86-77af-4623-bfe5-b85cc2dd4585" xlink:to="loc_us-gaap_NoncontrollingInterestMember_03133217-6eae-43f4-b601-e933f47ff742" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/CONSOLIDATEDSTATEMENTSOFSHAREHOLDERSEQUITYParenthetical" xlink:type="simple" xlink:href="wab-20201231.xsd#CONSOLIDATEDSTATEMENTSOFSHAREHOLDERSEQUITYParenthetical"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/CONSOLIDATEDSTATEMENTSOFSHAREHOLDERSEQUITYParenthetical" xlink:type="extended" id="i34332e197d6843c18fa9d853bfab3505_CONSOLIDATEDSTATEMENTSOFSHAREHOLDERSEQUITYParenthetical"/>
  <link:roleRef roleURI="http://wabtec.com/role/BUSINESS" xlink:type="simple" xlink:href="wab-20201231.xsd#BUSINESS"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/BUSINESS" xlink:type="extended" id="i242218e3222b437a9e8b7d3cc31e6460_BUSINESS"/>
  <link:roleRef roleURI="http://wabtec.com/role/BUSINESSNarrativeDetails" xlink:type="simple" xlink:href="wab-20201231.xsd#BUSINESSNarrativeDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/BUSINESSNarrativeDetails" xlink:type="extended" id="i423ab15d89394aacb35dbd5a10f12c42_BUSINESSNarrativeDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProductInformationLineItems_45e33892-957e-4490-855c-880bb256b70c" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ProductInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NumberOfCountriesInWhichEntityOperates_ddd2060b-eb4c-40be-8347-190e5a06f7c5" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NumberOfCountriesInWhichEntityOperates"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ProductInformationLineItems_45e33892-957e-4490-855c-880bb256b70c" xlink:to="loc_us-gaap_NumberOfCountriesInWhichEntityOperates_ddd2060b-eb4c-40be-8347-190e5a06f7c5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_NumberOfCountriesWhereProductFound_2aab56ea-8483-4de8-ba1d-fd592591ff76" xlink:href="wab-20201231.xsd#wab_NumberOfCountriesWhereProductFound"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ProductInformationLineItems_45e33892-957e-4490-855c-880bb256b70c" xlink:to="loc_wab_NumberOfCountriesWhereProductFound_2aab56ea-8483-4de8-ba1d-fd592591ff76" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskPercentage1_4d30345c-e3b5-4fe5-9029-5013bf29688d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ConcentrationRiskPercentage1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ProductInformationLineItems_45e33892-957e-4490-855c-880bb256b70c" xlink:to="loc_us-gaap_ConcentrationRiskPercentage1_4d30345c-e3b5-4fe5-9029-5013bf29688d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfProductInformationTable_05cd3d42-8521-48ce-b92c-99f0ad218d84" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfProductInformationTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ProductInformationLineItems_45e33892-957e-4490-855c-880bb256b70c" xlink:to="loc_us-gaap_ScheduleOfProductInformationTable_05cd3d42-8521-48ce-b92c-99f0ad218d84" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_56ca4574-faf4-4b55-8611-c4548f45df65" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ConcentrationRiskByBenchmarkAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfProductInformationTable_05cd3d42-8521-48ce-b92c-99f0ad218d84" xlink:to="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_56ca4574-faf4-4b55-8611-c4548f45df65" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_56ca4574-faf4-4b55-8611-c4548f45df65_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_56ca4574-faf4-4b55-8611-c4548f45df65" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_56ca4574-faf4-4b55-8611-c4548f45df65_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_2cd5c7a4-5411-4a0f-83ee-dcbb4b80a69d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_56ca4574-faf4-4b55-8611-c4548f45df65" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_2cd5c7a4-5411-4a0f-83ee-dcbb4b80a69d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerMember_0e45460f-9ff9-4b4d-b648-7d8e8bdd9d73" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevenueFromContractWithCustomerMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskBenchmarkDomain_2cd5c7a4-5411-4a0f-83ee-dcbb4b80a69d" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerMember_0e45460f-9ff9-4b4d-b648-7d8e8bdd9d73" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByTypeAxis_2d61e351-1305-431d-9b18-7ac92ceecdc0" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ConcentrationRiskByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfProductInformationTable_05cd3d42-8521-48ce-b92c-99f0ad218d84" xlink:to="loc_us-gaap_ConcentrationRiskByTypeAxis_2d61e351-1305-431d-9b18-7ac92ceecdc0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_2d61e351-1305-431d-9b18-7ac92ceecdc0_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_2d61e351-1305-431d-9b18-7ac92ceecdc0" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_2d61e351-1305-431d-9b18-7ac92ceecdc0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_3a28ab58-9ef0-4c25-8d61-250c4480fcc4" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_2d61e351-1305-431d-9b18-7ac92ceecdc0" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_3a28ab58-9ef0-4c25-8d61-250c4480fcc4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeographicConcentrationRiskMember_0f4829ab-1cf7-47f1-b5cd-d3c81bcead67" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_GeographicConcentrationRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskTypeDomain_3a28ab58-9ef0-4c25-8d61-250c4480fcc4" xlink:to="loc_us-gaap_GeographicConcentrationRiskMember_0f4829ab-1cf7-47f1-b5cd-d3c81bcead67" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis_241029cd-d10c-488f-8d62-d6ff51e38bc3" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_StatementGeographicalAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfProductInformationTable_05cd3d42-8521-48ce-b92c-99f0ad218d84" xlink:to="loc_srt_StatementGeographicalAxis_241029cd-d10c-488f-8d62-d6ff51e38bc3" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_241029cd-d10c-488f-8d62-d6ff51e38bc3_default" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_241029cd-d10c-488f-8d62-d6ff51e38bc3" xlink:to="loc_srt_SegmentGeographicalDomain_241029cd-d10c-488f-8d62-d6ff51e38bc3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_c813e3db-7b40-4157-8c03-68339736ccfd" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_241029cd-d10c-488f-8d62-d6ff51e38bc3" xlink:to="loc_srt_SegmentGeographicalDomain_c813e3db-7b40-4157-8c03-68339736ccfd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonUsMember_d9ef0980-a906-4533-bc5b-6ed0aca331da" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NonUsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_c813e3db-7b40-4157-8c03-68339736ccfd" xlink:to="loc_us-gaap_NonUsMember_d9ef0980-a906-4533-bc5b-6ed0aca331da" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIES" xlink:type="simple" xlink:href="wab-20201231.xsd#SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIES"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIES" xlink:type="extended" id="ic69a3f4f42814f8e8c5c1d9ec02c99da_SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIES"/>
  <link:roleRef roleURI="http://wabtec.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESPolicies" xlink:type="simple" xlink:href="wab-20201231.xsd#SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESPolicies"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESPolicies" xlink:type="extended" id="id0cf5d277df542f094ec4d0952755e87_SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESPolicies"/>
  <link:roleRef roleURI="http://wabtec.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESTables" xlink:type="simple" xlink:href="wab-20201231.xsd#SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESTables"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESTables" xlink:type="extended" id="ic8698f398086442494fcc9c2ccc97c8a_SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESTables"/>
  <link:roleRef roleURI="http://wabtec.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails" xlink:type="simple" xlink:href="wab-20201231.xsd#SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails" xlink:type="extended" id="i7154ad2f673343ceae2cfff972631727_SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails">
    <link:loc xlink:type="locator" xlink:label="loc_wab_SummaryOfSignificantAccountingPoliciesLineItems_3791b88e-4407-4f32-b336-940684d14953" xlink:href="wab-20201231.xsd#wab_SummaryOfSignificantAccountingPoliciesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProvisionForDoubtfulAccounts_59a21e6c-4ff7-44a4-baef-0cfef4cc7b40" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ProvisionForDoubtfulAccounts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_wab_SummaryOfSignificantAccountingPoliciesLineItems_3791b88e-4407-4f32-b336-940684d14953" xlink:to="loc_us-gaap_ProvisionForDoubtfulAccounts_59a21e6c-4ff7-44a4-baef-0cfef4cc7b40" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityMethodInvestments_7c665996-80c5-497c-85d8-5b93ab58ddbf" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EquityMethodInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_wab_SummaryOfSignificantAccountingPoliciesLineItems_3791b88e-4407-4f32-b336-940684d14953" xlink:to="loc_us-gaap_EquityMethodInvestments_7c665996-80c5-497c-85d8-5b93ab58ddbf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignCurrencyTransactionGainLossRealized_4b02421e-a3c1-437a-ad1a-66b12a5b667f" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ForeignCurrencyTransactionGainLossRealized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_wab_SummaryOfSignificantAccountingPoliciesLineItems_3791b88e-4407-4f32-b336-940684d14953" xlink:to="loc_us-gaap_ForeignCurrencyTransactionGainLossRealized_4b02421e-a3c1-437a-ad1a-66b12a5b667f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_AccountsReceivableAfterAllowanceForCreditLossMaximumRecurringTransfer_847b8597-1afd-4013-be2c-d41714b190fc" xlink:href="wab-20201231.xsd#wab_AccountsReceivableAfterAllowanceForCreditLossMaximumRecurringTransfer"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_wab_SummaryOfSignificantAccountingPoliciesLineItems_3791b88e-4407-4f32-b336-940684d14953" xlink:to="loc_wab_AccountsReceivableAfterAllowanceForCreditLossMaximumRecurringTransfer_847b8597-1afd-4013-be2c-d41714b190fc" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsReceivableNetCurrent_2e16cc62-c8c2-4f9a-896a-09a914423a5a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccountsReceivableNetCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_wab_SummaryOfSignificantAccountingPoliciesLineItems_3791b88e-4407-4f32-b336-940684d14953" xlink:to="loc_us-gaap_AccountsReceivableNetCurrent_2e16cc62-c8c2-4f9a-896a-09a914423a5a" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnbilledReceivablesCurrent_ad8b246b-1f7c-4ece-b5b7-2b3bb8c17102" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_UnbilledReceivablesCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_wab_SummaryOfSignificantAccountingPoliciesLineItems_3791b88e-4407-4f32-b336-940684d14953" xlink:to="loc_us-gaap_UnbilledReceivablesCurrent_ad8b246b-1f7c-4ece-b5b7-2b3bb8c17102" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreproductionCostsRelatedToLongTermSupplyArrangementsCostsCapitalized_8bea08ab-497a-4421-912d-b56acb37f3b5" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PreproductionCostsRelatedToLongTermSupplyArrangementsCostsCapitalized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_wab_SummaryOfSignificantAccountingPoliciesLineItems_3791b88e-4407-4f32-b336-940684d14953" xlink:to="loc_us-gaap_PreproductionCostsRelatedToLongTermSupplyArrangementsCostsCapitalized_8bea08ab-497a-4421-912d-b56acb37f3b5" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesAuthorized_b854adec-f184-46bc-9352-ec06ef803969" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PreferredStockSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_wab_SummaryOfSignificantAccountingPoliciesLineItems_3791b88e-4407-4f32-b336-940684d14953" xlink:to="loc_us-gaap_PreferredStockSharesAuthorized_b854adec-f184-46bc-9352-ec06ef803969" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesIssued_ecba4c14-46cf-43a4-9ad5-aa0234e9ed61" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PreferredStockSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_wab_SummaryOfSignificantAccountingPoliciesLineItems_3791b88e-4407-4f32-b336-940684d14953" xlink:to="loc_us-gaap_PreferredStockSharesIssued_ecba4c14-46cf-43a4-9ad5-aa0234e9ed61" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesOutstanding_c11971b2-8706-4e0d-92ea-1caf85aa8aed" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PreferredStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_wab_SummaryOfSignificantAccountingPoliciesLineItems_3791b88e-4407-4f32-b336-940684d14953" xlink:to="loc_us-gaap_PreferredStockSharesOutstanding_c11971b2-8706-4e0d-92ea-1caf85aa8aed" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_SummaryOfSignificantAccountingPoliciesTable_b193538d-1ca5-4f3a-ae58-08cfc6d588d1" xlink:href="wab-20201231.xsd#wab_SummaryOfSignificantAccountingPoliciesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_wab_SummaryOfSignificantAccountingPoliciesLineItems_3791b88e-4407-4f32-b336-940684d14953" xlink:to="loc_wab_SummaryOfSignificantAccountingPoliciesTable_b193538d-1ca5-4f3a-ae58-08cfc6d588d1" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CollateralAxis_394261ff-f63c-45b3-ab63-5f0f2579b51b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CollateralAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_wab_SummaryOfSignificantAccountingPoliciesTable_b193538d-1ca5-4f3a-ae58-08cfc6d588d1" xlink:to="loc_us-gaap_CollateralAxis_394261ff-f63c-45b3-ab63-5f0f2579b51b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CollateralDomain_394261ff-f63c-45b3-ab63-5f0f2579b51b_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CollateralDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CollateralAxis_394261ff-f63c-45b3-ab63-5f0f2579b51b" xlink:to="loc_us-gaap_CollateralDomain_394261ff-f63c-45b3-ab63-5f0f2579b51b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CollateralDomain_4d307971-7bf6-43de-94ba-9a4972d198e7" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CollateralDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CollateralAxis_394261ff-f63c-45b3-ab63-5f0f2579b51b" xlink:to="loc_us-gaap_CollateralDomain_4d307971-7bf6-43de-94ba-9a4972d198e7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CollateralPledgedMember_cba041ba-3426-474c-843d-0e69e801f485" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CollateralPledgedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CollateralDomain_4d307971-7bf6-43de-94ba-9a4972d198e7" xlink:to="loc_us-gaap_CollateralPledgedMember_cba041ba-3426-474c-843d-0e69e801f485" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESPerformanceObligationDetails" xlink:type="simple" xlink:href="wab-20201231.xsd#SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESPerformanceObligationDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESPerformanceObligationDetails" xlink:type="extended" id="i49471351b2794775b72d0d1e44c74c29_SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESPerformanceObligationDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_495de690-5d44-4ef4-a774-0ff894c800f7" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligation_fa59896a-c45d-4b4e-9622-3bb9fe2a6de5" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_495de690-5d44-4ef4-a774-0ff894c800f7" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligation_fa59896a-c45d-4b4e-9622-3bb9fe2a6de5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationPercentage_539fb0ff-0a20-4cf2-bc24-c9273f21f65e" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligationPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_495de690-5d44-4ef4-a774-0ff894c800f7" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationPercentage_539fb0ff-0a20-4cf2-bc24-c9273f21f65e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_4eb5f5dd-735f-4823-a827-d876c1988f73" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_495de690-5d44-4ef4-a774-0ff894c800f7" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_4eb5f5dd-735f-4823-a827-d876c1988f73" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_35faf676-0e04-4f3d-9a97-e68c3652133d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_495de690-5d44-4ef4-a774-0ff894c800f7" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_35faf676-0e04-4f3d-9a97-e68c3652133d" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis_1b045f39-329b-4eac-a8d4-9ec23a12e710" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_35faf676-0e04-4f3d-9a97-e68c3652133d" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis_1b045f39-329b-4eac-a8d4-9ec23a12e710" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESPerformanceObligationDetails_1" xlink:type="simple" xlink:href="wab-20201231.xsd#SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESPerformanceObligationDetails_1"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESPerformanceObligationDetails_1" xlink:type="extended" id="iea3b64e7f3994e73b138d1c09a8bc24d_SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESPerformanceObligationDetails_1">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_495de690-5d44-4ef4-a774-0ff894c800f7" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligation_fa59896a-c45d-4b4e-9622-3bb9fe2a6de5" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_495de690-5d44-4ef4-a774-0ff894c800f7" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligation_fa59896a-c45d-4b4e-9622-3bb9fe2a6de5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationPercentage_539fb0ff-0a20-4cf2-bc24-c9273f21f65e" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligationPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_495de690-5d44-4ef4-a774-0ff894c800f7" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationPercentage_539fb0ff-0a20-4cf2-bc24-c9273f21f65e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_4eb5f5dd-735f-4823-a827-d876c1988f73" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_495de690-5d44-4ef4-a774-0ff894c800f7" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_4eb5f5dd-735f-4823-a827-d876c1988f73" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_35faf676-0e04-4f3d-9a97-e68c3652133d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_495de690-5d44-4ef4-a774-0ff894c800f7" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_35faf676-0e04-4f3d-9a97-e68c3652133d" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESSummaryofReceivablesSoldDetails" xlink:type="simple" xlink:href="wab-20201231.xsd#SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESSummaryofReceivablesSoldDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESSummaryofReceivablesSoldDetails" xlink:type="extended" id="iff2d3ae33d604b9eb35ce81bfa5d4b60_SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESSummaryofReceivablesSoldDetails"/>
  <link:roleRef roleURI="http://wabtec.com/role/ACQUISITIONS" xlink:type="simple" xlink:href="wab-20201231.xsd#ACQUISITIONS"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/ACQUISITIONS" xlink:type="extended" id="id44de7b8ddbc402799108ff6e76489c0_ACQUISITIONS"/>
  <link:roleRef roleURI="http://wabtec.com/role/ACQUISITIONSTables" xlink:type="simple" xlink:href="wab-20201231.xsd#ACQUISITIONSTables"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/ACQUISITIONSTables" xlink:type="extended" id="ic68078aa335d443e9f34b14c77ee7193_ACQUISITIONSTables"/>
  <link:roleRef roleURI="http://wabtec.com/role/ACQUISITIONSNarrativeDetails" xlink:type="simple" xlink:href="wab-20201231.xsd#ACQUISITIONSNarrativeDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/ACQUISITIONSNarrativeDetails" xlink:type="extended" id="iefc9a61f2a5f46eba339e493530e448f_ACQUISITIONSNarrativeDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_9197df8a-05bc-492f-afdb-eba418d9a30c" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_BusinessCombinationConsiderationTransferredCertainIdentifiableAssetsofAcquired_3bdbbb23-db65-4961-92cf-7f18f2646445" xlink:href="wab-20201231.xsd#wab_BusinessCombinationConsiderationTransferredCertainIdentifiableAssetsofAcquired"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_9197df8a-05bc-492f-afdb-eba418d9a30c" xlink:to="loc_wab_BusinessCombinationConsiderationTransferredCertainIdentifiableAssetsofAcquired_3bdbbb23-db65-4961-92cf-7f18f2646445" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_66ce25ec-c314-44c6-baad-a5977d6be0c9" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_9197df8a-05bc-492f-afdb-eba418d9a30c" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_66ce25ec-c314-44c6-baad-a5977d6be0c9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesOutstanding_8969943d-1ab9-451f-93b6-4f137da7981b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PreferredStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_9197df8a-05bc-492f-afdb-eba418d9a30c" xlink:to="loc_us-gaap_PreferredStockSharesOutstanding_8969943d-1ab9-451f-93b6-4f137da7981b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued_90387cce-1f76-4a1d-a163-2602d38e0416" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_9197df8a-05bc-492f-afdb-eba418d9a30c" xlink:to="loc_us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued_90387cce-1f76-4a1d-a163-2602d38e0416" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_BusinessCombinationPercentageofOutstandingSharesTransferred_97c773b3-cb49-446d-b7a0-7a6ea4b8dcea" xlink:href="wab-20201231.xsd#wab_BusinessCombinationPercentageofOutstandingSharesTransferred"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_9197df8a-05bc-492f-afdb-eba418d9a30c" xlink:to="loc_wab_BusinessCombinationPercentageofOutstandingSharesTransferred_97c773b3-cb49-446d-b7a0-7a6ea4b8dcea" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireBusinessesGross_6fb211b3-23f9-4dcb-a462-4beb32b37fec" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PaymentsToAcquireBusinessesGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_9197df8a-05bc-492f-afdb-eba418d9a30c" xlink:to="loc_us-gaap_PaymentsToAcquireBusinessesGross_6fb211b3-23f9-4dcb-a462-4beb32b37fec" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesIssued_506d8533-76a1-4b6b-b031-b8a1237fa1c0" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CommonStockSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_9197df8a-05bc-492f-afdb-eba418d9a30c" xlink:to="loc_us-gaap_CommonStockSharesIssued_506d8533-76a1-4b6b-b031-b8a1237fa1c0" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesIssued_99848767-758e-41bf-aec1-0a81109da3a3" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PreferredStockSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_9197df8a-05bc-492f-afdb-eba418d9a30c" xlink:to="loc_us-gaap_PreferredStockSharesIssued_99848767-758e-41bf-aec1-0a81109da3a3" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction_3c35c1f1-abc9-44f1-8e41-e84038a13706" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_9197df8a-05bc-492f-afdb-eba418d9a30c" xlink:to="loc_us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction_3c35c1f1-abc9-44f1-8e41-e84038a13706" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferred1_9701f298-5b35-4275-8046-39e8e11cd88f" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationConsiderationTransferred1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_9197df8a-05bc-492f-afdb-eba418d9a30c" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferred1_9701f298-5b35-4275-8046-39e8e11cd88f" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionSharePrice_b579e796-27bd-401e-9675-4f9ac328adb7" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionSharePrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_9197df8a-05bc-492f-afdb-eba418d9a30c" xlink:to="loc_us-gaap_BusinessAcquisitionSharePrice_b579e796-27bd-401e-9675-4f9ac328adb7" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationAcquisitionOfLessThan100PercentNoncontrollingInterestFairValue_1878746f-a8b4-4069-99df-c5cd22db9231" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationAcquisitionOfLessThan100PercentNoncontrollingInterestFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_9197df8a-05bc-492f-afdb-eba418d9a30c" xlink:to="loc_us-gaap_BusinessCombinationAcquisitionOfLessThan100PercentNoncontrollingInterestFairValue_1878746f-a8b4-4069-99df-c5cd22db9231" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther_073f49c4-8479-4055-b5ee-52dc15834fd2" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_9197df8a-05bc-492f-afdb-eba418d9a30c" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther_073f49c4-8479-4055-b5ee-52dc15834fd2" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationAsset1_e070b590-bfe8-4a14-a728-0a2e26225690" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationAsset1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_9197df8a-05bc-492f-afdb-eba418d9a30c" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationAsset1_e070b590-bfe8-4a14-a728-0a2e26225690" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_d929d4ac-e58b-4beb-867c-4c5a3a053454" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_9197df8a-05bc-492f-afdb-eba418d9a30c" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_d929d4ac-e58b-4beb-867c-4c5a3a053454" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_a3566d00-1928-4e47-81b4-059f326c539c" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_d929d4ac-e58b-4beb-867c-4c5a3a053454" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_a3566d00-1928-4e47-81b4-059f326c539c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_a3566d00-1928-4e47-81b4-059f326c539c_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_a3566d00-1928-4e47-81b4-059f326c539c" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_a3566d00-1928-4e47-81b4-059f326c539c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_ae618570-3f54-485e-a092-226361a2f16e" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_a3566d00-1928-4e47-81b4-059f326c539c" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_ae618570-3f54-485e-a092-226361a2f16e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_GETransportationMember_80f34177-e718-46e0-b9ff-bbde1a1db4ed" xlink:href="wab-20201231.xsd#wab_GETransportationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_ae618570-3f54-485e-a092-226361a2f16e" xlink:to="loc_wab_GETransportationMember_80f34177-e718-46e0-b9ff-bbde1a1db4ed" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_GeneralElectricCompanyMember_cb9638d2-ec75-48b1-95e4-b49778deb597" xlink:href="wab-20201231.xsd#wab_GeneralElectricCompanyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_ae618570-3f54-485e-a092-226361a2f16e" xlink:to="loc_wab_GeneralElectricCompanyMember_cb9638d2-ec75-48b1-95e4-b49778deb597" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_GETBrazilMember_fbc5b4c4-20fe-42b2-b99a-cbe6577a9ae1" xlink:href="wab-20201231.xsd#wab_GETBrazilMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_ae618570-3f54-485e-a092-226361a2f16e" xlink:to="loc_wab_GETBrazilMember_fbc5b4c4-20fe-42b2-b99a-cbe6577a9ae1" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_46a1fe0a-54cd-4e24-a150-436f92879243" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_d929d4ac-e58b-4beb-867c-4c5a3a053454" xlink:to="loc_dei_LegalEntityAxis_46a1fe0a-54cd-4e24-a150-436f92879243" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_46a1fe0a-54cd-4e24-a150-436f92879243_default" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_46a1fe0a-54cd-4e24-a150-436f92879243" xlink:to="loc_dei_EntityDomain_46a1fe0a-54cd-4e24-a150-436f92879243_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_a366146b-0c05-439d-877a-a6672eedeb55" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_46a1fe0a-54cd-4e24-a150-436f92879243" xlink:to="loc_dei_EntityDomain_a366146b-0c05-439d-877a-a6672eedeb55" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_GeneralElectricCompanyMember_af4f128b-e2b2-45a5-8f0b-1551e9ee11ea" xlink:href="wab-20201231.xsd#wab_GeneralElectricCompanyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_a366146b-0c05-439d-877a-a6672eedeb55" xlink:to="loc_wab_GeneralElectricCompanyMember_af4f128b-e2b2-45a5-8f0b-1551e9ee11ea" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_PremergerWabtecStockholdersMember_1d39ad45-158f-44ec-98d5-02e70f61528f" xlink:href="wab-20201231.xsd#wab_PremergerWabtecStockholdersMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_a366146b-0c05-439d-877a-a6672eedeb55" xlink:to="loc_wab_PremergerWabtecStockholdersMember_1d39ad45-158f-44ec-98d5-02e70f61528f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_WabtecMember_21e5f3a1-c91b-4e5b-adb3-5033dc68c193" xlink:href="wab-20201231.xsd#wab_WabtecMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_a366146b-0c05-439d-877a-a6672eedeb55" xlink:to="loc_wab_WabtecMember_21e5f3a1-c91b-4e5b-adb3-5033dc68c193" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_b06f56ef-82d2-4e59-9628-692f3af9e747" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_d929d4ac-e58b-4beb-867c-4c5a3a053454" xlink:to="loc_us-gaap_StatementClassOfStockAxis_b06f56ef-82d2-4e59-9628-692f3af9e747" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_b06f56ef-82d2-4e59-9628-692f3af9e747_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_b06f56ef-82d2-4e59-9628-692f3af9e747" xlink:to="loc_us-gaap_ClassOfStockDomain_b06f56ef-82d2-4e59-9628-692f3af9e747_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_ac152c72-c610-41b4-ad61-03bfbf63dde0" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_b06f56ef-82d2-4e59-9628-692f3af9e747" xlink:to="loc_us-gaap_ClassOfStockDomain_ac152c72-c610-41b4-ad61-03bfbf63dde0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_SpinCoCommonStockMember_f6df9801-7cf3-40b7-a50e-8c1ff55f78a4" xlink:href="wab-20201231.xsd#wab_SpinCoCommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_ac152c72-c610-41b4-ad61-03bfbf63dde0" xlink:to="loc_wab_SpinCoCommonStockMember_f6df9801-7cf3-40b7-a50e-8c1ff55f78a4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_SpinCoClassAPreferredStockMember_aa5f1ad2-4938-4d52-8c30-d2c984a59995" xlink:href="wab-20201231.xsd#wab_SpinCoClassAPreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_ac152c72-c610-41b4-ad61-03bfbf63dde0" xlink:to="loc_wab_SpinCoClassAPreferredStockMember_aa5f1ad2-4938-4d52-8c30-d2c984a59995" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_SpinCoClassBPreferredStockMember_43dc1e03-b757-48a9-9c4d-2379bdbd7cb1" xlink:href="wab-20201231.xsd#wab_SpinCoClassBPreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_ac152c72-c610-41b4-ad61-03bfbf63dde0" xlink:to="loc_wab_SpinCoClassBPreferredStockMember_43dc1e03-b757-48a9-9c4d-2379bdbd7cb1" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_SpinCoClassCPreferredStockMember_6cb1ae8a-52d2-4548-a4d6-d04ea56f0a1c" xlink:href="wab-20201231.xsd#wab_SpinCoClassCPreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_ac152c72-c610-41b4-ad61-03bfbf63dde0" xlink:to="loc_wab_SpinCoClassCPreferredStockMember_6cb1ae8a-52d2-4548-a4d6-d04ea56f0a1c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConvertiblePreferredStockMember_a04e576c-8f7f-48dd-b6dd-14121af558aa" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ConvertiblePreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_ac152c72-c610-41b4-ad61-03bfbf63dde0" xlink:to="loc_us-gaap_ConvertiblePreferredStockMember_a04e576c-8f7f-48dd-b6dd-14121af558aa" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeriesAPreferredStockMember_776955af-d0d6-4721-a866-7dfda82614dd" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SeriesAPreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_ac152c72-c610-41b4-ad61-03bfbf63dde0" xlink:to="loc_us-gaap_SeriesAPreferredStockMember_776955af-d0d6-4721-a866-7dfda82614dd" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_ca66aa7d-677d-49d3-9a6d-3205cf427e62" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_ac152c72-c610-41b4-ad61-03bfbf63dde0" xlink:to="loc_us-gaap_CommonStockMember_ca66aa7d-677d-49d3-9a6d-3205cf427e62" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_OwnershipAxis_a040d84c-93d7-491d-8912-3d572adc83f6" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_OwnershipAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_d929d4ac-e58b-4beb-867c-4c5a3a053454" xlink:to="loc_srt_OwnershipAxis_a040d84c-93d7-491d-8912-3d572adc83f6" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_OwnershipDomain_a040d84c-93d7-491d-8912-3d572adc83f6_default" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_OwnershipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_OwnershipAxis_a040d84c-93d7-491d-8912-3d572adc83f6" xlink:to="loc_srt_OwnershipDomain_a040d84c-93d7-491d-8912-3d572adc83f6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_OwnershipDomain_8e985db8-7410-476c-bb33-cfcbef0fa28a" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_OwnershipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_OwnershipAxis_a040d84c-93d7-491d-8912-3d572adc83f6" xlink:to="loc_srt_OwnershipDomain_8e985db8-7410-476c-bb33-cfcbef0fa28a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_GeneralElectricCompanyMember_5695b356-76b1-4966-b38c-c827ed9f6215" xlink:href="wab-20201231.xsd#wab_GeneralElectricCompanyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_OwnershipDomain_8e985db8-7410-476c-bb33-cfcbef0fa28a" xlink:to="loc_wab_GeneralElectricCompanyMember_5695b356-76b1-4966-b38c-c827ed9f6215" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_GEandPreMergerHoldersMember_1af4447d-2b9c-409a-b0ab-bd8d91dd4701" xlink:href="wab-20201231.xsd#wab_GEandPreMergerHoldersMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_OwnershipDomain_8e985db8-7410-476c-bb33-cfcbef0fa28a" xlink:to="loc_wab_GEandPreMergerHoldersMember_1af4447d-2b9c-409a-b0ab-bd8d91dd4701" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByLiabilityClassAxis_c9463030-3333-4694-b257-a1ecc935737b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueByLiabilityClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_d929d4ac-e58b-4beb-867c-4c5a3a053454" xlink:to="loc_us-gaap_FairValueByLiabilityClassAxis_c9463030-3333-4694-b257-a1ecc935737b" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_c9463030-3333-4694-b257-a1ecc935737b_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByLiabilityClassAxis_c9463030-3333-4694-b257-a1ecc935737b" xlink:to="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_c9463030-3333-4694-b257-a1ecc935737b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_1d088027-e42d-4070-8953-a02427b1b241" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByLiabilityClassAxis_c9463030-3333-4694-b257-a1ecc935737b" xlink:to="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_1d088027-e42d-4070-8953-a02427b1b241" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerContractsMember_9c6254e7-8b1f-41b7-af03-2113dc317cac" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CustomerContractsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_1d088027-e42d-4070-8953-a02427b1b241" xlink:to="loc_us-gaap_CustomerContractsMember_9c6254e7-8b1f-41b7-af03-2113dc317cac" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/ACQUISITIONSSummaryofFairValueofAssetsAcquiredandLiabilitiesAssumedDetails" xlink:type="simple" xlink:href="wab-20201231.xsd#ACQUISITIONSSummaryofFairValueofAssetsAcquiredandLiabilitiesAssumedDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/ACQUISITIONSSummaryofFairValueofAssetsAcquiredandLiabilitiesAssumedDetails" xlink:type="extended" id="i69dad921fe3b47e3b4bbf8c5ed6efc27_ACQUISITIONSSummaryofFairValueofAssetsAcquiredandLiabilitiesAssumedDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_f9216886-5da6-416e-ac5f-6b9b5718e424" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_3f0ef0d0-d318-41c0-9ace-2a4ccd1d08a4" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_f9216886-5da6-416e-ac5f-6b9b5718e424" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_3f0ef0d0-d318-41c0-9ace-2a4ccd1d08a4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents_874e4fc5-a11b-4453-8b82-29c58e1f91f7" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_3f0ef0d0-d318-41c0-9ace-2a4ccd1d08a4" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents_874e4fc5-a11b-4453-8b82-29c58e1f91f7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables_f3f0995b-89b2-4c4f-ba4b-a75119ee318f" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_3f0ef0d0-d318-41c0-9ace-2a4ccd1d08a4" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables_f3f0995b-89b2-4c4f-ba4b-a75119ee318f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory_39395903-ccbc-4aae-878b-c52a778525d3" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_3f0ef0d0-d318-41c0-9ace-2a4ccd1d08a4" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory_39395903-ccbc-4aae-878b-c52a778525d3" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsOther_3c5c8a14-1667-4319-8882-018c3a1cc83b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsOther"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_3f0ef0d0-d318-41c0-9ace-2a4ccd1d08a4" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsOther_3c5c8a14-1667-4319-8882-018c3a1cc83b" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment_45293ebd-27d3-46d7-967e-40dbf98b98eb" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_3f0ef0d0-d318-41c0-9ace-2a4ccd1d08a4" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment_45293ebd-27d3-46d7-967e-40dbf98b98eb" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_5767c077-297f-4167-ada0-88f2439c80a3" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_Goodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_3f0ef0d0-d318-41c0-9ace-2a4ccd1d08a4" xlink:to="loc_us-gaap_Goodwill_5767c077-297f-4167-ada0-88f2439c80a3" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_4c687a87-d354-44c1-8a83-1df758385ea5" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_3f0ef0d0-d318-41c0-9ace-2a4ccd1d08a4" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_4c687a87-d354-44c1-8a83-1df758385ea5" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherNoncurrentAssets_0e948028-353c-4343-893b-dcad0523480d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherNoncurrentAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_3f0ef0d0-d318-41c0-9ace-2a4ccd1d08a4" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherNoncurrentAssets_0e948028-353c-4343-893b-dcad0523480d" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets_32b87574-dbb6-4e5e-877e-bef457e2d714" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_3f0ef0d0-d318-41c0-9ace-2a4ccd1d08a4" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssets_32b87574-dbb6-4e5e-877e-bef457e2d714" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilitiesAbstract_bda1738b-9f31-4a75-a279-12280214b655" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilitiesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_f9216886-5da6-416e-ac5f-6b9b5718e424" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilitiesAbstract_bda1738b-9f31-4a75-a279-12280214b655" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities_3b1f6ef2-49bf-4224-8233-e33c43e8817d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilitiesAbstract_bda1738b-9f31-4a75-a279-12280214b655" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities_3b1f6ef2-49bf-4224-8233-e33c43e8817d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationLiability_48ecf5f5-6ecc-4b30-bd51-22c15e37130f" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationContingentConsiderationLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilitiesAbstract_bda1738b-9f31-4a75-a279-12280214b655" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationLiability_48ecf5f5-6ecc-4b30-bd51-22c15e37130f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther_c3486a56-3aa2-4535-a08f-7f11f7c82ddc" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilitiesAbstract_bda1738b-9f31-4a75-a279-12280214b655" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther_c3486a56-3aa2-4535-a08f-7f11f7c82ddc" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities_e29f8ee1-a590-45db-9ebb-ef32b1483026" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilitiesAbstract_bda1738b-9f31-4a75-a279-12280214b655" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities_e29f8ee1-a590-45db-9ebb-ef32b1483026" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedLessNoncontrollingInterest_79552487-2afd-436f-a74c-f56070a3534b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedLessNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_f9216886-5da6-416e-ac5f-6b9b5718e424" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedLessNoncontrollingInterest_79552487-2afd-436f-a74c-f56070a3534b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationAcquisitionOfLessThan100PercentNoncontrollingInterestFairValue_701e078e-88f0-4f17-9c97-abd7d857ee96" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationAcquisitionOfLessThan100PercentNoncontrollingInterestFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_f9216886-5da6-416e-ac5f-6b9b5718e424" xlink:to="loc_us-gaap_BusinessCombinationAcquisitionOfLessThan100PercentNoncontrollingInterestFairValue_701e078e-88f0-4f17-9c97-abd7d857ee96" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_ffdfd78b-d8e8-4a11-93e1-53273fe7159c" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_f9216886-5da6-416e-ac5f-6b9b5718e424" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_ffdfd78b-d8e8-4a11-93e1-53273fe7159c" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_9d4592a8-7598-4b85-add0-633c585343d0" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_ffdfd78b-d8e8-4a11-93e1-53273fe7159c" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_9d4592a8-7598-4b85-add0-633c585343d0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_9d4592a8-7598-4b85-add0-633c585343d0_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_9d4592a8-7598-4b85-add0-633c585343d0" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_9d4592a8-7598-4b85-add0-633c585343d0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_765ad53f-370f-42cb-bf4d-07c5fe71b1e6" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_9d4592a8-7598-4b85-add0-633c585343d0" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_765ad53f-370f-42cb-bf4d-07c5fe71b1e6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_GeneralElectricCompanyMember_746cf594-2cda-4d17-88c7-fad8285a874b" xlink:href="wab-20201231.xsd#wab_GeneralElectricCompanyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_765ad53f-370f-42cb-bf4d-07c5fe71b1e6" xlink:to="loc_wab_GeneralElectricCompanyMember_746cf594-2cda-4d17-88c7-fad8285a874b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_36bc457a-0d67-441d-a179-6326f7835306" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_ffdfd78b-d8e8-4a11-93e1-53273fe7159c" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_36bc457a-0d67-441d-a179-6326f7835306" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_36bc457a-0d67-441d-a179-6326f7835306_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_36bc457a-0d67-441d-a179-6326f7835306" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_36bc457a-0d67-441d-a179-6326f7835306_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_396a5d01-353e-4b1d-a331-4bbf91338388" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_36bc457a-0d67-441d-a179-6326f7835306" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_396a5d01-353e-4b1d-a331-4bbf91338388" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TradeNamesMember_5b171652-74de-498d-aa59-83e1b2eed297" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TradeNamesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_396a5d01-353e-4b1d-a331-4bbf91338388" xlink:to="loc_us-gaap_TradeNamesMember_5b171652-74de-498d-aa59-83e1b2eed297" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerRelationshipsMember_99f72c69-0077-43ca-a1e4-ec56cf96ed89" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CustomerRelationshipsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_396a5d01-353e-4b1d-a331-4bbf91338388" xlink:to="loc_us-gaap_CustomerRelationshipsMember_99f72c69-0077-43ca-a1e4-ec56cf96ed89" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntellectualPropertyMember_df0b099a-c15b-4c3f-a162-69c2d6d22358" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IntellectualPropertyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_396a5d01-353e-4b1d-a331-4bbf91338388" xlink:to="loc_us-gaap_IntellectualPropertyMember_df0b099a-c15b-4c3f-a162-69c2d6d22358" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OrderOrProductionBacklogMember_b900d817-f712-42ff-923c-7724fc459c43" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OrderOrProductionBacklogMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_396a5d01-353e-4b1d-a331-4bbf91338388" xlink:to="loc_us-gaap_OrderOrProductionBacklogMember_b900d817-f712-42ff-923c-7724fc459c43" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_4b232932-1073-41cb-8808-4c031af1494c" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_ffdfd78b-d8e8-4a11-93e1-53273fe7159c" xlink:to="loc_dei_LegalEntityAxis_4b232932-1073-41cb-8808-4c031af1494c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_4b232932-1073-41cb-8808-4c031af1494c_default" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_4b232932-1073-41cb-8808-4c031af1494c" xlink:to="loc_dei_EntityDomain_4b232932-1073-41cb-8808-4c031af1494c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_14610dae-04cf-4d5e-9b98-f2c18827ea72" xlink:href="https://xbrl.sec.gov/dei/2020/dei-2020-01-31.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_4b232932-1073-41cb-8808-4c031af1494c" xlink:to="loc_dei_EntityDomain_14610dae-04cf-4d5e-9b98-f2c18827ea72" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_GeneralElectricCompanyMember_fd45837e-f905-451b-9357-3881946bcdad" xlink:href="wab-20201231.xsd#wab_GeneralElectricCompanyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_14610dae-04cf-4d5e-9b98-f2c18827ea72" xlink:to="loc_wab_GeneralElectricCompanyMember_fd45837e-f905-451b-9357-3881946bcdad" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/ACQUISITIONSProFormaFinancialInformationDetails" xlink:type="simple" xlink:href="wab-20201231.xsd#ACQUISITIONSProFormaFinancialInformationDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/ACQUISITIONSProFormaFinancialInformationDetails" xlink:type="extended" id="i6b3ad62c6f7a4b819c04b48ab90efeb6_ACQUISITIONSProFormaFinancialInformationDetails"/>
  <link:roleRef roleURI="http://wabtec.com/role/SUPPLEMENTALCASHFLOWDISCLOSURES" xlink:type="simple" xlink:href="wab-20201231.xsd#SUPPLEMENTALCASHFLOWDISCLOSURES"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/SUPPLEMENTALCASHFLOWDISCLOSURES" xlink:type="extended" id="ic09b1f4cd48b42f89dfa7df09d942569_SUPPLEMENTALCASHFLOWDISCLOSURES"/>
  <link:roleRef roleURI="http://wabtec.com/role/SUPPLEMENTALCASHFLOWDISCLOSURESTables" xlink:type="simple" xlink:href="wab-20201231.xsd#SUPPLEMENTALCASHFLOWDISCLOSURESTables"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/SUPPLEMENTALCASHFLOWDISCLOSURESTables" xlink:type="extended" id="i60865e149b00471d8b2f23e414a2f8f3_SUPPLEMENTALCASHFLOWDISCLOSURESTables"/>
  <link:roleRef roleURI="http://wabtec.com/role/SUPPLEMENTALCASHFLOWDISCLOSURESDetails" xlink:type="simple" xlink:href="wab-20201231.xsd#SUPPLEMENTALCASHFLOWDISCLOSURESDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/SUPPLEMENTALCASHFLOWDISCLOSURESDetails" xlink:type="extended" id="i1c723288f88d423c8973b63b4036523f_SUPPLEMENTALCASHFLOWDISCLOSURESDetails"/>
  <link:roleRef roleURI="http://wabtec.com/role/INVENTORIES" xlink:type="simple" xlink:href="wab-20201231.xsd#INVENTORIES"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/INVENTORIES" xlink:type="extended" id="i3af237d46a56462f929903ebff89ae00_INVENTORIES"/>
  <link:roleRef roleURI="http://wabtec.com/role/INVENTORIESTables" xlink:type="simple" xlink:href="wab-20201231.xsd#INVENTORIESTables"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/INVENTORIESTables" xlink:type="extended" id="i9e4fbfa389ab47d596f83ee7f0991ceb_INVENTORIESTables"/>
  <link:roleRef roleURI="http://wabtec.com/role/INVENTORIESComponentsofInventoryNetofReservesDetails" xlink:type="simple" xlink:href="wab-20201231.xsd#INVENTORIESComponentsofInventoryNetofReservesDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/INVENTORIESComponentsofInventoryNetofReservesDetails" xlink:type="extended" id="ia7b27714e9b94c01a0f6c9f707b8532a_INVENTORIESComponentsofInventoryNetofReservesDetails"/>
  <link:roleRef roleURI="http://wabtec.com/role/PROPERTYPLANTEQUIPMENT" xlink:type="simple" xlink:href="wab-20201231.xsd#PROPERTYPLANTEQUIPMENT"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/PROPERTYPLANTEQUIPMENT" xlink:type="extended" id="ic58e6f15a1fc47f3a29b55effc8edf82_PROPERTYPLANTEQUIPMENT"/>
  <link:roleRef roleURI="http://wabtec.com/role/PROPERTYPLANTEQUIPMENTTables" xlink:type="simple" xlink:href="wab-20201231.xsd#PROPERTYPLANTEQUIPMENTTables"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/PROPERTYPLANTEQUIPMENTTables" xlink:type="extended" id="ia143ab32fcf840b1b4cf77f9060ed2b2_PROPERTYPLANTEQUIPMENTTables"/>
  <link:roleRef roleURI="http://wabtec.com/role/PROPERTYPLANTEQUIPMENTMajorClassesofDepreciableAssetsDetails" xlink:type="simple" xlink:href="wab-20201231.xsd#PROPERTYPLANTEQUIPMENTMajorClassesofDepreciableAssetsDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/PROPERTYPLANTEQUIPMENTMajorClassesofDepreciableAssetsDetails" xlink:type="extended" id="i3818db1c903d4947bbd1577ceed6b008_PROPERTYPLANTEQUIPMENTMajorClassesofDepreciableAssetsDetails"/>
  <link:roleRef roleURI="http://wabtec.com/role/PROPERTYPLANTEQUIPMENTEstimatedUsefulLivesofPropertyPlantandEquipmentDetails" xlink:type="simple" xlink:href="wab-20201231.xsd#PROPERTYPLANTEQUIPMENTEstimatedUsefulLivesofPropertyPlantandEquipmentDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/PROPERTYPLANTEQUIPMENTEstimatedUsefulLivesofPropertyPlantandEquipmentDetails" xlink:type="extended" id="if10722cbca0c4e5b9f78e85407570431_PROPERTYPLANTEQUIPMENTEstimatedUsefulLivesofPropertyPlantandEquipmentDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentLineItems_38f12358-82ee-48b1-ac40-f93fc0a30a63" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentUsefulLife_0c56ada3-ac9d-473d-bd4c-f1a3a6f8717d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentUsefulLife"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_38f12358-82ee-48b1-ac40-f93fc0a30a63" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentUsefulLife_0c56ada3-ac9d-473d-bd4c-f1a3a6f8717d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_800f21c7-3ad6-497c-bb99-54400b93065e" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_38f12358-82ee-48b1-ac40-f93fc0a30a63" xlink:to="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_800f21c7-3ad6-497c-bb99-54400b93065e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_20e2f1c1-e855-46d9-950d-66b0ad20dd44" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_800f21c7-3ad6-497c-bb99-54400b93065e" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_20e2f1c1-e855-46d9-950d-66b0ad20dd44" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_20e2f1c1-e855-46d9-950d-66b0ad20dd44_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_20e2f1c1-e855-46d9-950d-66b0ad20dd44" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_20e2f1c1-e855-46d9-950d-66b0ad20dd44_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_97193bc5-2dc8-403f-9d83-5802a1fc95f0" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_20e2f1c1-e855-46d9-950d-66b0ad20dd44" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_97193bc5-2dc8-403f-9d83-5802a1fc95f0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LandImprovementsMember_8474cc29-4482-46a8-8fdc-5684d9d4c8e7" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LandImprovementsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_97193bc5-2dc8-403f-9d83-5802a1fc95f0" xlink:to="loc_us-gaap_LandImprovementsMember_8474cc29-4482-46a8-8fdc-5684d9d4c8e7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BuildingAndBuildingImprovementsMember_66fdb2df-23fa-4219-9b6f-053eb7143a95" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BuildingAndBuildingImprovementsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_97193bc5-2dc8-403f-9d83-5802a1fc95f0" xlink:to="loc_us-gaap_BuildingAndBuildingImprovementsMember_66fdb2df-23fa-4219-9b6f-053eb7143a95" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MachineryAndEquipmentMember_19809f48-dca1-497a-888b-22546095b5a2" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_MachineryAndEquipmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_97193bc5-2dc8-403f-9d83-5802a1fc95f0" xlink:to="loc_us-gaap_MachineryAndEquipmentMember_19809f48-dca1-497a-888b-22546095b5a2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_9c1fe2d6-1361-4cf1-8e52-04657be2445f" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_800f21c7-3ad6-497c-bb99-54400b93065e" xlink:to="loc_srt_RangeAxis_9c1fe2d6-1361-4cf1-8e52-04657be2445f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_9c1fe2d6-1361-4cf1-8e52-04657be2445f_default" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_9c1fe2d6-1361-4cf1-8e52-04657be2445f" xlink:to="loc_srt_RangeMember_9c1fe2d6-1361-4cf1-8e52-04657be2445f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_113de5f0-f06a-45fd-a78c-6e08008f920a" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_9c1fe2d6-1361-4cf1-8e52-04657be2445f" xlink:to="loc_srt_RangeMember_113de5f0-f06a-45fd-a78c-6e08008f920a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_fb12dd59-417f-4397-9d11-88b7b73aefdd" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_113de5f0-f06a-45fd-a78c-6e08008f920a" xlink:to="loc_srt_MinimumMember_fb12dd59-417f-4397-9d11-88b7b73aefdd" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_25843860-a4a0-4a4e-b6e1-5446bbd51e2b" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_113de5f0-f06a-45fd-a78c-6e08008f920a" xlink:to="loc_srt_MaximumMember_25843860-a4a0-4a4e-b6e1-5446bbd51e2b" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/PROPERTYPLANTEQUIPMENTNarrativeDetails" xlink:type="simple" xlink:href="wab-20201231.xsd#PROPERTYPLANTEQUIPMENTNarrativeDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/PROPERTYPLANTEQUIPMENTNarrativeDetails" xlink:type="extended" id="i4b0e3fc9cd35471b9e2848d8f07d9a21_PROPERTYPLANTEQUIPMENTNarrativeDetails"/>
  <link:roleRef roleURI="http://wabtec.com/role/INTANGIBLES" xlink:type="simple" xlink:href="wab-20201231.xsd#INTANGIBLES"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/INTANGIBLES" xlink:type="extended" id="i288b113c6b07422784d95ec57e576c70_INTANGIBLES"/>
  <link:roleRef roleURI="http://wabtec.com/role/INTANGIBLESTables" xlink:type="simple" xlink:href="wab-20201231.xsd#INTANGIBLESTables"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/INTANGIBLESTables" xlink:type="extended" id="i108ca8ebfe1f46ef8d14d104c3bbcc2c_INTANGIBLESTables"/>
  <link:roleRef roleURI="http://wabtec.com/role/INTANGIBLESChangeintheCarryingAmountofGoodwillbySegmentDetails" xlink:type="simple" xlink:href="wab-20201231.xsd#INTANGIBLESChangeintheCarryingAmountofGoodwillbySegmentDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/INTANGIBLESChangeintheCarryingAmountofGoodwillbySegmentDetails" xlink:type="extended" id="id1d1f6f3ae454250bfe9faf1975150a8_INTANGIBLESChangeintheCarryingAmountofGoodwillbySegmentDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillLineItems_81123269-b3d3-430b-a7d9-4744723dc063" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_GoodwillLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillRollForward_9a374525-dc0f-4b92-a1c4-740acf90d13f" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_GoodwillRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_81123269-b3d3-430b-a7d9-4744723dc063" xlink:to="loc_us-gaap_GoodwillRollForward_9a374525-dc0f-4b92-a1c4-740acf90d13f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_2dd44f47-6fae-4785-a492-4c77a8ea13c8" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_Goodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_9a374525-dc0f-4b92-a1c4-740acf90d13f" xlink:to="loc_us-gaap_Goodwill_2dd44f47-6fae-4785-a492-4c77a8ea13c8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillAcquiredDuringPeriod_7913ebed-03f3-4d20-89b3-7c005426269c" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_GoodwillAcquiredDuringPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_9a374525-dc0f-4b92-a1c4-740acf90d13f" xlink:to="loc_us-gaap_GoodwillAcquiredDuringPeriod_7913ebed-03f3-4d20-89b3-7c005426269c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_GoodwillDisposals_c46d372f-2d35-4f37-9004-cb160126643c" xlink:href="wab-20201231.xsd#wab_GoodwillDisposals"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_9a374525-dc0f-4b92-a1c4-740acf90d13f" xlink:to="loc_wab_GoodwillDisposals_c46d372f-2d35-4f37-9004-cb160126643c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillForeignCurrencyTranslationGainLoss_82d92371-ade9-40b8-878b-6146740d8552" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_GoodwillForeignCurrencyTranslationGainLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_9a374525-dc0f-4b92-a1c4-740acf90d13f" xlink:to="loc_us-gaap_GoodwillForeignCurrencyTranslationGainLoss_82d92371-ade9-40b8-878b-6146740d8552" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_bed51db1-a1f6-4a8c-aba4-4b8e747d2c2c" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_Goodwill"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfGoodwillTable_a3faada3-e428-4adb-b28a-64f63ae841d6" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfGoodwillTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_GoodwillLineItems_81123269-b3d3-430b-a7d9-4744723dc063" xlink:to="loc_us-gaap_ScheduleOfGoodwillTable_a3faada3-e428-4adb-b28a-64f63ae841d6" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_3960d566-b9ec-4523-a4de-87deed308996" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfGoodwillTable_a3faada3-e428-4adb-b28a-64f63ae841d6" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_3960d566-b9ec-4523-a4de-87deed308996" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_3960d566-b9ec-4523-a4de-87deed308996_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_3960d566-b9ec-4523-a4de-87deed308996" xlink:to="loc_us-gaap_SegmentDomain_3960d566-b9ec-4523-a4de-87deed308996_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_6d0f0dcc-3b7d-43bf-9bdc-3170bbccf579" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_3960d566-b9ec-4523-a4de-87deed308996" xlink:to="loc_us-gaap_SegmentDomain_6d0f0dcc-3b7d-43bf-9bdc-3170bbccf579" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_FreightSegmentMember_7ba50e7d-b88e-45e0-85a2-93cb277d6d28" xlink:href="wab-20201231.xsd#wab_FreightSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_6d0f0dcc-3b7d-43bf-9bdc-3170bbccf579" xlink:to="loc_wab_FreightSegmentMember_7ba50e7d-b88e-45e0-85a2-93cb277d6d28" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_TransitSegmentMember_fa86c007-6747-4039-87ed-8bc56ccaf977" xlink:href="wab-20201231.xsd#wab_TransitSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_6d0f0dcc-3b7d-43bf-9bdc-3170bbccf579" xlink:to="loc_wab_TransitSegmentMember_fa86c007-6747-4039-87ed-8bc56ccaf977" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/INTANGIBLESNarrativeDetails" xlink:type="simple" xlink:href="wab-20201231.xsd#INTANGIBLESNarrativeDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/INTANGIBLESNarrativeDetails" xlink:type="extended" id="i6850601322b344b0b438662d39cce2c9_INTANGIBLESNarrativeDetails">
    <link:loc xlink:type="locator" xlink:label="loc_wab_IntangibleAssetsDisclosureLineItems_ad4d1003-11a7-4c4e-a325-0d9ca93decca" xlink:href="wab-20201231.xsd#wab_IntangibleAssetsDisclosureLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_GoodwillImpairmentTestWeightOfApproach_53fbc08c-4fae-4e85-b180-738e4435d277" xlink:href="wab-20201231.xsd#wab_GoodwillImpairmentTestWeightOfApproach"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_wab_IntangibleAssetsDisclosureLineItems_ad4d1003-11a7-4c4e-a325-0d9ca93decca" xlink:to="loc_wab_GoodwillImpairmentTestWeightOfApproach_53fbc08c-4fae-4e85-b180-738e4435d277" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IndefiniteLivedTradeNames_7df28652-31a1-4772-8d9c-0fa380f7cbf6" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IndefiniteLivedTradeNames"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_wab_IntangibleAssetsDisclosureLineItems_ad4d1003-11a7-4c4e-a325-0d9ca93decca" xlink:to="loc_us-gaap_IndefiniteLivedTradeNames_7df28652-31a1-4772-8d9c-0fa380f7cbf6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetUsefulLife_c5130e0c-0925-4fed-a479-c95dba29488a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetUsefulLife"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_wab_IntangibleAssetsDisclosureLineItems_ad4d1003-11a7-4c4e-a325-0d9ca93decca" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetUsefulLife_c5130e0c-0925-4fed-a479-c95dba29488a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsRemainingAmortizationPeriod1_e9e1a3a1-62d0-4ecf-9bb9-1e0440be0b2f" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsRemainingAmortizationPeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_wab_IntangibleAssetsDisclosureLineItems_ad4d1003-11a7-4c4e-a325-0d9ca93decca" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsRemainingAmortizationPeriod1_e9e1a3a1-62d0-4ecf-9bb9-1e0440be0b2f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfIntangibleAssets_1a4ea9c6-abdf-4a77-9a65-e8c37efe0648" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AmortizationOfIntangibleAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_wab_IntangibleAssetsDisclosureLineItems_ad4d1003-11a7-4c4e-a325-0d9ca93decca" xlink:to="loc_us-gaap_AmortizationOfIntangibleAssets_1a4ea9c6-abdf-4a77-9a65-e8c37efe0648" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_IntangibleAssetsDisclosureTable_39e16145-2dd2-4ee1-8977-49bebc3387a4" xlink:href="wab-20201231.xsd#wab_IntangibleAssetsDisclosureTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_wab_IntangibleAssetsDisclosureLineItems_ad4d1003-11a7-4c4e-a325-0d9ca93decca" xlink:to="loc_wab_IntangibleAssetsDisclosureTable_39e16145-2dd2-4ee1-8977-49bebc3387a4" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_5d55723e-9e2e-4ed9-979e-29c2e47759ed" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_wab_IntangibleAssetsDisclosureTable_39e16145-2dd2-4ee1-8977-49bebc3387a4" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_5d55723e-9e2e-4ed9-979e-29c2e47759ed" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_5d55723e-9e2e-4ed9-979e-29c2e47759ed_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_5d55723e-9e2e-4ed9-979e-29c2e47759ed" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_5d55723e-9e2e-4ed9-979e-29c2e47759ed_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_2818d376-b1d7-4144-8364-5e4c9703d9f0" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_5d55723e-9e2e-4ed9-979e-29c2e47759ed" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_2818d376-b1d7-4144-8364-5e4c9703d9f0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TradeNamesMember_e135388c-3a22-45ff-bb8c-881bfa49a319" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_TradeNamesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_2818d376-b1d7-4144-8364-5e4c9703d9f0" xlink:to="loc_us-gaap_TradeNamesMember_e135388c-3a22-45ff-bb8c-881bfa49a319" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OrderOrProductionBacklogMember_b1767fa0-9043-4007-b43d-3bd1ce714a75" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OrderOrProductionBacklogMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_2818d376-b1d7-4144-8364-5e4c9703d9f0" xlink:to="loc_us-gaap_OrderOrProductionBacklogMember_b1767fa0-9043-4007-b43d-3bd1ce714a75" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntellectualPropertyMember_7bf75f11-2c23-43ed-9c48-ddcf36adb47a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IntellectualPropertyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_2818d376-b1d7-4144-8364-5e4c9703d9f0" xlink:to="loc_us-gaap_IntellectualPropertyMember_7bf75f11-2c23-43ed-9c48-ddcf36adb47a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerRelationshipsMember_f9de744b-289d-4dc2-92c1-9d1b0a930474" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CustomerRelationshipsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_2818d376-b1d7-4144-8364-5e4c9703d9f0" xlink:to="loc_us-gaap_CustomerRelationshipsMember_f9de744b-289d-4dc2-92c1-9d1b0a930474" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherIntangibleAssetsMember_d557f66c-6a12-4722-8bf6-d956d6918b07" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherIntangibleAssetsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_2818d376-b1d7-4144-8364-5e4c9703d9f0" xlink:to="loc_us-gaap_OtherIntangibleAssetsMember_d557f66c-6a12-4722-8bf6-d956d6918b07" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationTechniqueAxis_7eecadc7-0cd2-4c5a-ac16-7539a9906ab0" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ValuationTechniqueAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_wab_IntangibleAssetsDisclosureTable_39e16145-2dd2-4ee1-8977-49bebc3387a4" xlink:to="loc_us-gaap_ValuationTechniqueAxis_7eecadc7-0cd2-4c5a-ac16-7539a9906ab0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationTechniqueDomain_7eecadc7-0cd2-4c5a-ac16-7539a9906ab0_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ValuationTechniqueDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ValuationTechniqueAxis_7eecadc7-0cd2-4c5a-ac16-7539a9906ab0" xlink:to="loc_us-gaap_ValuationTechniqueDomain_7eecadc7-0cd2-4c5a-ac16-7539a9906ab0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationTechniqueDomain_b864c89d-c4ef-4344-821e-6f71d4f425e5" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ValuationTechniqueDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ValuationTechniqueAxis_7eecadc7-0cd2-4c5a-ac16-7539a9906ab0" xlink:to="loc_us-gaap_ValuationTechniqueDomain_b864c89d-c4ef-4344-821e-6f71d4f425e5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationTechniqueDiscountedCashFlowMember_2c969216-159a-47ae-8454-3c6785871294" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ValuationTechniqueDiscountedCashFlowMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ValuationTechniqueDomain_b864c89d-c4ef-4344-821e-6f71d4f425e5" xlink:to="loc_us-gaap_ValuationTechniqueDiscountedCashFlowMember_2c969216-159a-47ae-8454-3c6785871294" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MarketApproachValuationTechniqueMember_2085370f-5754-45c8-adaa-d8f74a415a26" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_MarketApproachValuationTechniqueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ValuationTechniqueDomain_b864c89d-c4ef-4344-821e-6f71d4f425e5" xlink:to="loc_us-gaap_MarketApproachValuationTechniqueMember_2085370f-5754-45c8-adaa-d8f74a415a26" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/INTANGIBLESIntangibleAssetsOtherThanGoodwillandTrademarksDetails" xlink:type="simple" xlink:href="wab-20201231.xsd#INTANGIBLESIntangibleAssetsOtherThanGoodwillandTrademarksDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/INTANGIBLESIntangibleAssetsOtherThanGoodwillandTrademarksDetails" xlink:type="extended" id="i79a392a67ced4c229cddf1ad0039d016_INTANGIBLESIntangibleAssetsOtherThanGoodwillandTrademarksDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_b26cae12-d6c6-472a-825c-2605fa86782e" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNet_3b3cfbe3-4b2c-4e03-9698-124e35c7a433" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_b26cae12-d6c6-472a-825c-2605fa86782e" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsNet_3b3cfbe3-4b2c-4e03-9698-124e35c7a433" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_72bb8b02-dd00-4455-b7b5-f92c98f54934" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_b26cae12-d6c6-472a-825c-2605fa86782e" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_72bb8b02-dd00-4455-b7b5-f92c98f54934" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_0930cd96-303b-482b-9015-74a7623bc22e" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_b26cae12-d6c6-472a-825c-2605fa86782e" xlink:to="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_0930cd96-303b-482b-9015-74a7623bc22e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_0b6da474-e24d-477b-86b6-71bbbfbc687c" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_0930cd96-303b-482b-9015-74a7623bc22e" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_0b6da474-e24d-477b-86b6-71bbbfbc687c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_0b6da474-e24d-477b-86b6-71bbbfbc687c_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_0b6da474-e24d-477b-86b6-71bbbfbc687c" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_0b6da474-e24d-477b-86b6-71bbbfbc687c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_1cfa318f-a65a-47d8-95ef-cd3fb37cdde2" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_0b6da474-e24d-477b-86b6-71bbbfbc687c" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_1cfa318f-a65a-47d8-95ef-cd3fb37cdde2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_IntellectualPropertyPatentsAndOtherMember_f9ecc199-f374-4c75-9001-acd57bf1d055" xlink:href="wab-20201231.xsd#wab_IntellectualPropertyPatentsAndOtherMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_1cfa318f-a65a-47d8-95ef-cd3fb37cdde2" xlink:to="loc_wab_IntellectualPropertyPatentsAndOtherMember_f9ecc199-f374-4c75-9001-acd57bf1d055" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OrderOrProductionBacklogMember_f6bc974a-15a9-415f-856a-0425f18c36d4" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OrderOrProductionBacklogMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_1cfa318f-a65a-47d8-95ef-cd3fb37cdde2" xlink:to="loc_us-gaap_OrderOrProductionBacklogMember_f6bc974a-15a9-415f-856a-0425f18c36d4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerRelationshipsMember_3fa652bb-2be9-471e-b00b-aa6dee19d97e" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CustomerRelationshipsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_1cfa318f-a65a-47d8-95ef-cd3fb37cdde2" xlink:to="loc_us-gaap_CustomerRelationshipsMember_3fa652bb-2be9-471e-b00b-aa6dee19d97e" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/INTANGIBLESEstimatedAmortizationExpenseFiveSucceedingYearsDetails" xlink:type="simple" xlink:href="wab-20201231.xsd#INTANGIBLESEstimatedAmortizationExpenseFiveSucceedingYearsDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/INTANGIBLESEstimatedAmortizationExpenseFiveSucceedingYearsDetails" xlink:type="extended" id="i047a6d5d50044e2bb5c052b54f9082d4_INTANGIBLESEstimatedAmortizationExpenseFiveSucceedingYearsDetails"/>
  <link:roleRef roleURI="http://wabtec.com/role/CONTRACTASSETSANDCONTRACTLIABILITIES" xlink:type="simple" xlink:href="wab-20201231.xsd#CONTRACTASSETSANDCONTRACTLIABILITIES"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/CONTRACTASSETSANDCONTRACTLIABILITIES" xlink:type="extended" id="i6f34c65880124875a1f602c31c263429_CONTRACTASSETSANDCONTRACTLIABILITIES"/>
  <link:roleRef roleURI="http://wabtec.com/role/CONTRACTASSETSANDCONTRACTLIABILITIESTables" xlink:type="simple" xlink:href="wab-20201231.xsd#CONTRACTASSETSANDCONTRACTLIABILITIESTables"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/CONTRACTASSETSANDCONTRACTLIABILITIESTables" xlink:type="extended" id="i9418e98c23514723a4eed2f59818a376_CONTRACTASSETSANDCONTRACTLIABILITIESTables"/>
  <link:roleRef roleURI="http://wabtec.com/role/CONTRACTASSETSANDCONTRACTLIABILITIESNarrativeDetails" xlink:type="simple" xlink:href="wab-20201231.xsd#CONTRACTASSETSANDCONTRACTLIABILITIESNarrativeDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/CONTRACTASSETSANDCONTRACTLIABILITIESNarrativeDetails" xlink:type="extended" id="if93d8996b6194d04b9c62cd1ac61d61b_CONTRACTASSETSANDCONTRACTLIABILITIESNarrativeDetails"/>
  <link:roleRef roleURI="http://wabtec.com/role/CONTRACTASSETSANDCONTRACTLIABILITIESContractwithCustomerAssetandLiabilityDetails" xlink:type="simple" xlink:href="wab-20201231.xsd#CONTRACTASSETSANDCONTRACTLIABILITIESContractwithCustomerAssetandLiabilityDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/CONTRACTASSETSANDCONTRACTLIABILITIESContractwithCustomerAssetandLiabilityDetails" xlink:type="extended" id="i3295d7c4f5064938bc71c0040d71efbc_CONTRACTASSETSANDCONTRACTLIABILITIESContractwithCustomerAssetandLiabilityDetails"/>
  <link:roleRef roleURI="http://wabtec.com/role/LONGTERMDEBT" xlink:type="simple" xlink:href="wab-20201231.xsd#LONGTERMDEBT"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/LONGTERMDEBT" xlink:type="extended" id="ic420c43008a94ab59d66b65d7441e0a4_LONGTERMDEBT"/>
  <link:roleRef roleURI="http://wabtec.com/role/LONGTERMDEBTTables" xlink:type="simple" xlink:href="wab-20201231.xsd#LONGTERMDEBTTables"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/LONGTERMDEBTTables" xlink:type="extended" id="i044eca85483e49568497e73a7ba55a73_LONGTERMDEBTTables"/>
  <link:roleRef roleURI="http://wabtec.com/role/LONGTERMDEBTScheduleofLongtermDebtDetails" xlink:type="simple" xlink:href="wab-20201231.xsd#LONGTERMDEBTScheduleofLongtermDebtDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/LONGTERMDEBTScheduleofLongtermDebtDetails" xlink:type="extended" id="i00644db321484941929c361904541cfb_LONGTERMDEBTScheduleofLongtermDebtDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_371f715d-586b-4a59-a4a7-889532d427f6" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateEffectivePercentage_1d00ba56-85fb-4a0c-a2f0-b19ed2a5258e" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentInterestRateEffectivePercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_371f715d-586b-4a59-a4a7-889532d427f6" xlink:to="loc_us-gaap_DebtInstrumentInterestRateEffectivePercentage_1d00ba56-85fb-4a0c-a2f0-b19ed2a5258e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebt_818aa164-0f7e-4c1a-9f03-9f23aee6ea2b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_371f715d-586b-4a59-a4a7-889532d427f6" xlink:to="loc_us-gaap_LongTermDebt_818aa164-0f7e-4c1a-9f03-9f23aee6ea2b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtCurrent_5bceb887-aa25-4de6-a276-3830668c70fd" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongTermDebtCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_371f715d-586b-4a59-a4a7-889532d427f6" xlink:to="loc_us-gaap_LongTermDebtCurrent_5bceb887-aa25-4de6-a276-3830668c70fd" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtNoncurrent_3ec62328-8ebb-4cb8-898d-b1b4a3c48288" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongTermDebtNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_371f715d-586b-4a59-a4a7-889532d427f6" xlink:to="loc_us-gaap_LongTermDebtNoncurrent_3ec62328-8ebb-4cb8-898d-b1b4a3c48288" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet_d07e6d26-e500-469d-b666-63351c4e1beb" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_371f715d-586b-4a59-a4a7-889532d427f6" xlink:to="loc_us-gaap_DebtInstrumentUnamortizedDiscountPremiumAndDebtIssuanceCostsNet_d07e6d26-e500-469d-b666-63351c4e1beb" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_9eda498e-8702-4745-a6df-4e831461ac21" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_371f715d-586b-4a59-a4a7-889532d427f6" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_9eda498e-8702-4745-a6df-4e831461ac21" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_e5603167-6afe-4ded-8068-2bead5a7b53c" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_371f715d-586b-4a59-a4a7-889532d427f6" xlink:to="loc_us-gaap_DebtInstrumentTable_e5603167-6afe-4ded-8068-2bead5a7b53c" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_a9092631-3465-4132-abfc-1b9c4e683582" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_e5603167-6afe-4ded-8068-2bead5a7b53c" xlink:to="loc_us-gaap_DebtInstrumentAxis_a9092631-3465-4132-abfc-1b9c4e683582" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_a9092631-3465-4132-abfc-1b9c4e683582_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_a9092631-3465-4132-abfc-1b9c4e683582" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_a9092631-3465-4132-abfc-1b9c4e683582_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_a6a43096-22e7-4794-96fb-a02293384078" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_a9092631-3465-4132-abfc-1b9c4e683582" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_a6a43096-22e7-4794-96fb-a02293384078" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_USDollarDenominatedTermLoansMember_574cf8cf-ec65-418b-8055-bc56b9a18679" xlink:href="wab-20201231.xsd#wab_USDollarDenominatedTermLoansMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_a6a43096-22e7-4794-96fb-a02293384078" xlink:to="loc_wab_USDollarDenominatedTermLoansMember_574cf8cf-ec65-418b-8055-bc56b9a18679" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_MultiCurrencyRevolvingLoanFacilityMember_065b4770-0666-49b8-9dd6-f3f7c1e0ad54" xlink:href="wab-20201231.xsd#wab_MultiCurrencyRevolvingLoanFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_a6a43096-22e7-4794-96fb-a02293384078" xlink:to="loc_wab_MultiCurrencyRevolvingLoanFacilityMember_065b4770-0666-49b8-9dd6-f3f7c1e0ad54" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_FloatingRateNotesDue2021Member_e0bd6618-46fc-49f5-8c84-bca51ff41f78" xlink:href="wab-20201231.xsd#wab_FloatingRateNotesDue2021Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_a6a43096-22e7-4794-96fb-a02293384078" xlink:to="loc_wab_FloatingRateNotesDue2021Member_e0bd6618-46fc-49f5-8c84-bca51ff41f78" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_A4375PercentSeniorNotesDueTwoThousandAndTwentyThreeMember_a0e9644e-fa25-4a58-a274-e91992c5cdae" xlink:href="wab-20201231.xsd#wab_A4375PercentSeniorNotesDueTwoThousandAndTwentyThreeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_a6a43096-22e7-4794-96fb-a02293384078" xlink:to="loc_wab_A4375PercentSeniorNotesDueTwoThousandAndTwentyThreeMember_a0e9644e-fa25-4a58-a274-e91992c5cdae" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_A4150PercentSeniorNotesDueTwoThousandAndTwentyFourMember_2d96f9b7-422c-444a-99fb-5f1ae791b92f" xlink:href="wab-20201231.xsd#wab_A4150PercentSeniorNotesDueTwoThousandAndTwentyFourMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_a6a43096-22e7-4794-96fb-a02293384078" xlink:to="loc_wab_A4150PercentSeniorNotesDueTwoThousandAndTwentyFourMember_2d96f9b7-422c-444a-99fb-5f1ae791b92f" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_A32000PercentSeniorNotesDueTwoThousandAndTwentyFiveMember_65ba7a43-f9fe-4600-b441-25a8ff4a49a0" xlink:href="wab-20201231.xsd#wab_A32000PercentSeniorNotesDueTwoThousandAndTwentyFiveMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_a6a43096-22e7-4794-96fb-a02293384078" xlink:to="loc_wab_A32000PercentSeniorNotesDueTwoThousandAndTwentyFiveMember_65ba7a43-f9fe-4600-b441-25a8ff4a49a0" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_A3.45PercentSeniorNotesDueTwoThousandandTwentySixMember_8ca6433d-02a4-4bec-b944-68d7619895d7" xlink:href="wab-20201231.xsd#wab_A3.45PercentSeniorNotesDueTwoThousandandTwentySixMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_a6a43096-22e7-4794-96fb-a02293384078" xlink:to="loc_wab_A3.45PercentSeniorNotesDueTwoThousandandTwentySixMember_8ca6433d-02a4-4bec-b944-68d7619895d7" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_A470PercentSeniorNotesDueTwoThousandAndTwentySixMember_e19479ee-94bb-4427-86ea-5b0cad32d014" xlink:href="wab-20201231.xsd#wab_A470PercentSeniorNotesDueTwoThousandAndTwentySixMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_a6a43096-22e7-4794-96fb-a02293384078" xlink:to="loc_wab_A470PercentSeniorNotesDueTwoThousandAndTwentySixMember_e19479ee-94bb-4427-86ea-5b0cad32d014" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_bf17ed4f-57a8-4016-8cac-88b906ca1a88" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_e5603167-6afe-4ded-8068-2bead5a7b53c" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_bf17ed4f-57a8-4016-8cac-88b906ca1a88" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_bf17ed4f-57a8-4016-8cac-88b906ca1a88_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_bf17ed4f-57a8-4016-8cac-88b906ca1a88" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_bf17ed4f-57a8-4016-8cac-88b906ca1a88_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_f1857120-fe66-4470-a41a-4733c00c9e2b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_bf17ed4f-57a8-4016-8cac-88b906ca1a88" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_f1857120-fe66-4470-a41a-4733c00c9e2b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditMember_cb0c87df-19ae-4dae-98eb-e5aa3bc60a42" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LineOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_f1857120-fe66-4470-a41a-4733c00c9e2b" xlink:to="loc_us-gaap_LineOfCreditMember_cb0c87df-19ae-4dae-98eb-e5aa3bc60a42" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeniorNotesMember_e9ed1de6-5287-4911-bf71-285a4cf3fcf2" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SeniorNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_f1857120-fe66-4470-a41a-4733c00c9e2b" xlink:to="loc_us-gaap_SeniorNotesMember_e9ed1de6-5287-4911-bf71-285a4cf3fcf2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherDebtSecuritiesMember_08363429-5796-4afd-82a4-4fc0010aa7b6" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherDebtSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_f1857120-fe66-4470-a41a-4733c00c9e2b" xlink:to="loc_us-gaap_OtherDebtSecuritiesMember_08363429-5796-4afd-82a4-4fc0010aa7b6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_1439b01b-08fc-49cd-bdea-b3626fad642d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CreditFacilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_e5603167-6afe-4ded-8068-2bead5a7b53c" xlink:to="loc_us-gaap_CreditFacilityAxis_1439b01b-08fc-49cd-bdea-b3626fad642d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_1439b01b-08fc-49cd-bdea-b3626fad642d_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_1439b01b-08fc-49cd-bdea-b3626fad642d" xlink:to="loc_us-gaap_CreditFacilityDomain_1439b01b-08fc-49cd-bdea-b3626fad642d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_4980198d-cdbe-4ba8-ab26-a9bde60e9cd9" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_1439b01b-08fc-49cd-bdea-b3626fad642d" xlink:to="loc_us-gaap_CreditFacilityDomain_4980198d-cdbe-4ba8-ab26-a9bde60e9cd9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_14cb4aa3-93a9-4f32-9929-becc49ee0823" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevolvingCreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_4980198d-cdbe-4ba8-ab26-a9bde60e9cd9" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_14cb4aa3-93a9-4f32-9929-becc49ee0823" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByMeasurementBasisAxis_e6218b8a-caa8-4226-b318-1eb31ab3e3b8" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueByMeasurementBasisAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_e5603167-6afe-4ded-8068-2bead5a7b53c" xlink:to="loc_us-gaap_FairValueByMeasurementBasisAxis_e6218b8a-caa8-4226-b318-1eb31ab3e3b8" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_e6218b8a-caa8-4226-b318-1eb31ab3e3b8_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PortionAtFairValueFairValueDisclosureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByMeasurementBasisAxis_e6218b8a-caa8-4226-b318-1eb31ab3e3b8" xlink:to="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_e6218b8a-caa8-4226-b318-1eb31ab3e3b8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueDisclosureItemAmountsDomain_2ab8ff90-9ab2-443f-a639-a464a939577a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueDisclosureItemAmountsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByMeasurementBasisAxis_e6218b8a-caa8-4226-b318-1eb31ab3e3b8" xlink:to="loc_us-gaap_FairValueDisclosureItemAmountsDomain_2ab8ff90-9ab2-443f-a639-a464a939577a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_7b5baadb-7789-4e34-a9af-301ed1b2774e" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PortionAtFairValueFairValueDisclosureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueDisclosureItemAmountsDomain_2ab8ff90-9ab2-443f-a639-a464a939577a" xlink:to="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_7b5baadb-7789-4e34-a9af-301ed1b2774e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EstimateOfFairValueFairValueDisclosureMember_d037f89b-22de-416f-b9b2-160db9089da7" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EstimateOfFairValueFairValueDisclosureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueDisclosureItemAmountsDomain_2ab8ff90-9ab2-443f-a639-a464a939577a" xlink:to="loc_us-gaap_EstimateOfFairValueFairValueDisclosureMember_d037f89b-22de-416f-b9b2-160db9089da7" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/LONGTERMDEBTAnnualRepaymentRequirementsforDebtObligationsDetails" xlink:type="simple" xlink:href="wab-20201231.xsd#LONGTERMDEBTAnnualRepaymentRequirementsforDebtObligationsDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/LONGTERMDEBTAnnualRepaymentRequirementsforDebtObligationsDetails" xlink:type="extended" id="i204b507ebe804c958c6571566ffb82e3_LONGTERMDEBTAnnualRepaymentRequirementsforDebtObligationsDetails"/>
  <link:roleRef roleURI="http://wabtec.com/role/LONGTERMDEBTNarrativeDetails" xlink:type="simple" xlink:href="wab-20201231.xsd#LONGTERMDEBTNarrativeDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/LONGTERMDEBTNarrativeDetails" xlink:type="extended" id="ibb0d14c2bcbd4f73bd17e811b51c11f2_LONGTERMDEBTNarrativeDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_d6f0e492-f74d-4a63-b184-e40f1cdf52d1" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredFinanceCostsNet_3b875a46-bfed-4252-8481-1c67662419e6" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredFinanceCostsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_d6f0e492-f74d-4a63-b184-e40f1cdf52d1" xlink:to="loc_us-gaap_DeferredFinanceCostsNet_3b875a46-bfed-4252-8481-1c67662419e6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtWeightedAverageInterestRate_2b699c77-552d-4b2c-8e23-be401e4be63a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongtermDebtWeightedAverageInterestRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_d6f0e492-f74d-4a63-b184-e40f1cdf52d1" xlink:to="loc_us-gaap_LongtermDebtWeightedAverageInterestRate_2b699c77-552d-4b2c-8e23-be401e4be63a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_88741583-982c-4190-9bfd-5c19226f3975" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_d6f0e492-f74d-4a63-b184-e40f1cdf52d1" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_88741583-982c-4190-9bfd-5c19226f3975" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTerm_114e27d8-34e4-4faf-8edd-7186e959c97e" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentTerm"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_d6f0e492-f74d-4a63-b184-e40f1cdf52d1" xlink:to="loc_us-gaap_DebtInstrumentTerm_114e27d8-34e4-4faf-8edd-7186e959c97e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebt_1ceec821-0da2-41f8-8cd1-5577516189ac" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_d6f0e492-f74d-4a63-b184-e40f1cdf52d1" xlink:to="loc_us-gaap_LongTermDebt_1ceec821-0da2-41f8-8cd1-5577516189ac" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_91d15924-2c0a-4945-a057-67af55a9a4d8" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_d6f0e492-f74d-4a63-b184-e40f1cdf52d1" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_91d15924-2c0a-4945-a057-67af55a9a4d8" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentRedemptionPricePercentage_5350ac36-ab96-422c-b1f7-b6b3bca876ec" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentRedemptionPricePercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_d6f0e492-f74d-4a63-b184-e40f1cdf52d1" xlink:to="loc_us-gaap_DebtInstrumentRedemptionPricePercentage_5350ac36-ab96-422c-b1f7-b6b3bca876ec" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_d503131a-3a93-4225-94a5-1b782a6c60e7" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentFaceAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_d6f0e492-f74d-4a63-b184-e40f1cdf52d1" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_d503131a-3a93-4225-94a5-1b782a6c60e7" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredFinanceCostsGross_702079f2-5b4c-43a4-afe1-ee55b9fef7c8" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DeferredFinanceCostsGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_d6f0e492-f74d-4a63-b184-e40f1cdf52d1" xlink:to="loc_us-gaap_DeferredFinanceCostsGross_702079f2-5b4c-43a4-afe1-ee55b9fef7c8" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LettersOfCreditOutstandingAmount_eb90bbb1-d58f-43eb-9c2b-d19dd6887bef" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LettersOfCreditOutstandingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_d6f0e492-f74d-4a63-b184-e40f1cdf52d1" xlink:to="loc_us-gaap_LettersOfCreditOutstandingAmount_eb90bbb1-d58f-43eb-9c2b-d19dd6887bef" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_d7c22e6e-0ada-4da0-95a9-c959195a6a69" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_d6f0e492-f74d-4a63-b184-e40f1cdf52d1" xlink:to="loc_us-gaap_DebtInstrumentTable_d7c22e6e-0ada-4da0-95a9-c959195a6a69" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_d37d9d8f-8396-45a6-811f-cbdae23510fb" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_d7c22e6e-0ada-4da0-95a9-c959195a6a69" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_d37d9d8f-8396-45a6-811f-cbdae23510fb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_d37d9d8f-8396-45a6-811f-cbdae23510fb_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_d37d9d8f-8396-45a6-811f-cbdae23510fb" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_d37d9d8f-8396-45a6-811f-cbdae23510fb_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_38e31661-f5c6-475f-806c-023b1cec6e4d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_d37d9d8f-8396-45a6-811f-cbdae23510fb" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_38e31661-f5c6-475f-806c-023b1cec6e4d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeniorNotesMember_2d9f1a2d-163a-4010-a3bd-ed63a7921d84" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SeniorNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_38e31661-f5c6-475f-806c-023b1cec6e4d" xlink:to="loc_us-gaap_SeniorNotesMember_2d9f1a2d-163a-4010-a3bd-ed63a7921d84" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditMember_c0b750c2-264f-4866-929e-d0049b06cfd5" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LineOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_38e31661-f5c6-475f-806c-023b1cec6e4d" xlink:to="loc_us-gaap_LineOfCreditMember_c0b750c2-264f-4866-929e-d0049b06cfd5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_59e7a1f7-0930-4ead-b76f-16f95d4677fe" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_d7c22e6e-0ada-4da0-95a9-c959195a6a69" xlink:to="loc_us-gaap_DebtInstrumentAxis_59e7a1f7-0930-4ead-b76f-16f95d4677fe" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_59e7a1f7-0930-4ead-b76f-16f95d4677fe_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_59e7a1f7-0930-4ead-b76f-16f95d4677fe" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_59e7a1f7-0930-4ead-b76f-16f95d4677fe_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_e82caabe-231c-4f12-b1e7-0fd583fe03d9" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_59e7a1f7-0930-4ead-b76f-16f95d4677fe" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_e82caabe-231c-4f12-b1e7-0fd583fe03d9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_TwoThousandandEighteenRefinancingAgreementMember_7847d107-3986-4064-8829-bc6f8bd78ae8" xlink:href="wab-20201231.xsd#wab_TwoThousandandEighteenRefinancingAgreementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_e82caabe-231c-4f12-b1e7-0fd583fe03d9" xlink:to="loc_wab_TwoThousandandEighteenRefinancingAgreementMember_7847d107-3986-4064-8829-bc6f8bd78ae8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_TermLoanMember_db1666fa-a7d7-4bb2-9508-d7d008f54f18" xlink:href="wab-20201231.xsd#wab_TermLoanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_e82caabe-231c-4f12-b1e7-0fd583fe03d9" xlink:to="loc_wab_TermLoanMember_db1666fa-a7d7-4bb2-9508-d7d008f54f18" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_A4375PercentSeniorNotesDueTwoThousandAndTwentyThreeMember_ae9e469d-52ff-4b49-9f90-a4df23eb6962" xlink:href="wab-20201231.xsd#wab_A4375PercentSeniorNotesDueTwoThousandAndTwentyThreeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_e82caabe-231c-4f12-b1e7-0fd583fe03d9" xlink:to="loc_wab_A4375PercentSeniorNotesDueTwoThousandAndTwentyThreeMember_ae9e469d-52ff-4b49-9f90-a4df23eb6962" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_A4150PercentSeniorNotesDueTwoThousandAndTwentyFourMember_c5682e7b-eca4-450a-a068-523ab4cbfbea" xlink:href="wab-20201231.xsd#wab_A4150PercentSeniorNotesDueTwoThousandAndTwentyFourMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_e82caabe-231c-4f12-b1e7-0fd583fe03d9" xlink:to="loc_wab_A4150PercentSeniorNotesDueTwoThousandAndTwentyFourMember_c5682e7b-eca4-450a-a068-523ab4cbfbea" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_A32000PercentSeniorNotesDueTwoThousandAndTwentyFiveMember_f3ed6424-114a-49e1-b173-26836f0c18af" xlink:href="wab-20201231.xsd#wab_A32000PercentSeniorNotesDueTwoThousandAndTwentyFiveMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_e82caabe-231c-4f12-b1e7-0fd583fe03d9" xlink:to="loc_wab_A32000PercentSeniorNotesDueTwoThousandAndTwentyFiveMember_f3ed6424-114a-49e1-b173-26836f0c18af" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_A3.45PercentSeniorNotesDueTwoThousandandTwentySixMember_0e9afe43-f245-4e07-9df6-858a7f2ad6b6" xlink:href="wab-20201231.xsd#wab_A3.45PercentSeniorNotesDueTwoThousandandTwentySixMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_e82caabe-231c-4f12-b1e7-0fd583fe03d9" xlink:to="loc_wab_A3.45PercentSeniorNotesDueTwoThousandandTwentySixMember_0e9afe43-f245-4e07-9df6-858a7f2ad6b6" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_A470PercentSeniorNotesDueTwoThousandAndTwentySixMember_89b7251e-f1e6-452a-af45-bba827e45ed2" xlink:href="wab-20201231.xsd#wab_A470PercentSeniorNotesDueTwoThousandAndTwentySixMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_e82caabe-231c-4f12-b1e7-0fd583fe03d9" xlink:to="loc_wab_A470PercentSeniorNotesDueTwoThousandAndTwentySixMember_89b7251e-f1e6-452a-af45-bba827e45ed2" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_f38771d2-31fe-48a9-af5a-affa8f880b5b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CreditFacilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_d7c22e6e-0ada-4da0-95a9-c959195a6a69" xlink:to="loc_us-gaap_CreditFacilityAxis_f38771d2-31fe-48a9-af5a-affa8f880b5b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_f38771d2-31fe-48a9-af5a-affa8f880b5b_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_f38771d2-31fe-48a9-af5a-affa8f880b5b" xlink:to="loc_us-gaap_CreditFacilityDomain_f38771d2-31fe-48a9-af5a-affa8f880b5b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_cf300722-e2ff-49ee-abb7-6320c2e6e9af" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_f38771d2-31fe-48a9-af5a-affa8f880b5b" xlink:to="loc_us-gaap_CreditFacilityDomain_cf300722-e2ff-49ee-abb7-6320c2e6e9af" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_cc8233e3-527c-4787-91ac-19d4f729ecea" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevolvingCreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_cf300722-e2ff-49ee-abb7-6320c2e6e9af" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_cc8233e3-527c-4787-91ac-19d4f729ecea" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_SwingLineSubFacilityMember_d08ec98f-1154-47b3-bf30-d71cc2cb5197" xlink:href="wab-20201231.xsd#wab_SwingLineSubFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_cf300722-e2ff-49ee-abb7-6320c2e6e9af" xlink:to="loc_wab_SwingLineSubFacilityMember_d08ec98f-1154-47b3-bf30-d71cc2cb5197" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LetterOfCreditMember_e766f9cd-5ce1-43b2-a20c-60a58ec49b01" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LetterOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_cf300722-e2ff-49ee-abb7-6320c2e6e9af" xlink:to="loc_us-gaap_LetterOfCreditMember_e766f9cd-5ce1-43b2-a20c-60a58ec49b01" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_TermLoanMember_9b4eb60f-7e67-4716-9294-e24f0822676f" xlink:href="wab-20201231.xsd#wab_TermLoanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_cf300722-e2ff-49ee-abb7-6320c2e6e9af" xlink:to="loc_wab_TermLoanMember_9b4eb60f-7e67-4716-9294-e24f0822676f" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/LONGTERMDEBTInterestCoverageRatioLeverageRatioDetails" xlink:type="simple" xlink:href="wab-20201231.xsd#LONGTERMDEBTInterestCoverageRatioLeverageRatioDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/LONGTERMDEBTInterestCoverageRatioLeverageRatioDetails" xlink:type="extended" id="i78892b176ad84fe3959edf89ffb3aeec_LONGTERMDEBTInterestCoverageRatioLeverageRatioDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_0187a681-5a5a-4199-81fc-d0955990c7ba" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_DebtInstrumentRestrictiveCovenantsEBITDAtoInterestExpenseRatioMinimum_fdc4ed97-26ed-4abc-abfc-439e39d3b4d7" xlink:href="wab-20201231.xsd#wab_DebtInstrumentRestrictiveCovenantsEBITDAtoInterestExpenseRatioMinimum"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_0187a681-5a5a-4199-81fc-d0955990c7ba" xlink:to="loc_wab_DebtInstrumentRestrictiveCovenantsEBITDAtoInterestExpenseRatioMinimum_fdc4ed97-26ed-4abc-abfc-439e39d3b4d7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_DebtInstrumentRestrictiveCovenantsLeverageRatioMaximum_b62aa80f-a903-43eb-bdc0-b0062da635a5" xlink:href="wab-20201231.xsd#wab_DebtInstrumentRestrictiveCovenantsLeverageRatioMaximum"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_0187a681-5a5a-4199-81fc-d0955990c7ba" xlink:to="loc_wab_DebtInstrumentRestrictiveCovenantsLeverageRatioMaximum_b62aa80f-a903-43eb-bdc0-b0062da635a5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_9dbbb378-694b-4c9f-b64a-c3050c0971f0" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_0187a681-5a5a-4199-81fc-d0955990c7ba" xlink:to="loc_us-gaap_DebtInstrumentTable_9dbbb378-694b-4c9f-b64a-c3050c0971f0" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_4929a89e-9489-443f-8590-a6b6ace24b97" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_9dbbb378-694b-4c9f-b64a-c3050c0971f0" xlink:to="loc_us-gaap_DebtInstrumentAxis_4929a89e-9489-443f-8590-a6b6ace24b97" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_4929a89e-9489-443f-8590-a6b6ace24b97_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_4929a89e-9489-443f-8590-a6b6ace24b97" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_4929a89e-9489-443f-8590-a6b6ace24b97_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_a3bec7d4-48d2-4614-8a3f-fa29528d3729" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_4929a89e-9489-443f-8590-a6b6ace24b97" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_a3bec7d4-48d2-4614-8a3f-fa29528d3729" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_TwoThousandandEighteenRefinancingAgreementMember_ad9503e5-5b9e-40a7-b3b8-844560c8905c" xlink:href="wab-20201231.xsd#wab_TwoThousandandEighteenRefinancingAgreementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_a3bec7d4-48d2-4614-8a3f-fa29528d3729" xlink:to="loc_wab_TwoThousandandEighteenRefinancingAgreementMember_ad9503e5-5b9e-40a7-b3b8-844560c8905c" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/LONGTERMDEBTScheduleofLineofCreditFacilitiesDetails" xlink:type="simple" xlink:href="wab-20201231.xsd#LONGTERMDEBTScheduleofLineofCreditFacilitiesDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/LONGTERMDEBTScheduleofLineofCreditFacilitiesDetails" xlink:type="extended" id="i3fb0ce6a14a94376930a52c4894defbd_LONGTERMDEBTScheduleofLineofCreditFacilitiesDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_78c26c99-8d8d-4750-b721-148627b5e241" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_7d4375af-eb3a-4356-9db7-6b60c27333ec" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_78c26c99-8d8d-4750-b721-148627b5e241" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_7d4375af-eb3a-4356-9db7-6b60c27333ec" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LettersOfCreditOutstandingAmount_4b146fd6-a52e-49ec-b000-36096e5e57dc" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LettersOfCreditOutstandingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_78c26c99-8d8d-4750-b721-148627b5e241" xlink:to="loc_us-gaap_LettersOfCreditOutstandingAmount_4b146fd6-a52e-49ec-b000-36096e5e57dc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity_15dbf0c3-ff11-417d-887c-4ef6773b0672" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_78c26c99-8d8d-4750-b721-148627b5e241" xlink:to="loc_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity_15dbf0c3-ff11-417d-887c-4ef6773b0672" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_ad06d431-2464-4c60-87e4-0ebc2ae5afe0" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_78c26c99-8d8d-4750-b721-148627b5e241" xlink:to="loc_us-gaap_DebtInstrumentTable_ad06d431-2464-4c60-87e4-0ebc2ae5afe0" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_58278ba5-730d-4572-a5cb-50b6f1d500d6" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_ad06d431-2464-4c60-87e4-0ebc2ae5afe0" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_58278ba5-730d-4572-a5cb-50b6f1d500d6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_58278ba5-730d-4572-a5cb-50b6f1d500d6_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_58278ba5-730d-4572-a5cb-50b6f1d500d6" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_58278ba5-730d-4572-a5cb-50b6f1d500d6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_b63fa5f2-fdf5-4cec-bac9-800ae3846f21" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_58278ba5-730d-4572-a5cb-50b6f1d500d6" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_b63fa5f2-fdf5-4cec-bac9-800ae3846f21" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditMember_e4ee17f8-6a0b-47d2-a25d-fb0bf34405cb" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LineOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_b63fa5f2-fdf5-4cec-bac9-800ae3846f21" xlink:to="loc_us-gaap_LineOfCreditMember_e4ee17f8-6a0b-47d2-a25d-fb0bf34405cb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_108b3f87-10e6-488b-a9dd-e627137494fe" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CreditFacilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_ad06d431-2464-4c60-87e4-0ebc2ae5afe0" xlink:to="loc_us-gaap_CreditFacilityAxis_108b3f87-10e6-488b-a9dd-e627137494fe" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_108b3f87-10e6-488b-a9dd-e627137494fe_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_108b3f87-10e6-488b-a9dd-e627137494fe" xlink:to="loc_us-gaap_CreditFacilityDomain_108b3f87-10e6-488b-a9dd-e627137494fe_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_32dd0b03-01f6-42c7-83b5-4930c17b3d1c" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_108b3f87-10e6-488b-a9dd-e627137494fe" xlink:to="loc_us-gaap_CreditFacilityDomain_32dd0b03-01f6-42c7-83b5-4930c17b3d1c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_98681f8d-925c-4ab1-8471-92d9e11336bf" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevolvingCreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_32dd0b03-01f6-42c7-83b5-4930c17b3d1c" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_98681f8d-925c-4ab1-8471-92d9e11336bf" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_fc0abf9c-3112-413c-bd9c-606e837ebd53" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_ad06d431-2464-4c60-87e4-0ebc2ae5afe0" xlink:to="loc_us-gaap_DebtInstrumentAxis_fc0abf9c-3112-413c-bd9c-606e837ebd53" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_fc0abf9c-3112-413c-bd9c-606e837ebd53_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_fc0abf9c-3112-413c-bd9c-606e837ebd53" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_fc0abf9c-3112-413c-bd9c-606e837ebd53_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_fa2d074e-5c76-4883-a8b2-cc69f5a92d57" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_fc0abf9c-3112-413c-bd9c-606e837ebd53" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_fa2d074e-5c76-4883-a8b2-cc69f5a92d57" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_TwoThousandandEighteenRefinancingAgreementMember_d6851226-50ee-4c51-abd8-379cebab54fc" xlink:href="wab-20201231.xsd#wab_TwoThousandandEighteenRefinancingAgreementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_fa2d074e-5c76-4883-a8b2-cc69f5a92d57" xlink:to="loc_wab_TwoThousandandEighteenRefinancingAgreementMember_d6851226-50ee-4c51-abd8-379cebab54fc" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/EMPLOYEEBENEFITPLANS" xlink:type="simple" xlink:href="wab-20201231.xsd#EMPLOYEEBENEFITPLANS"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/EMPLOYEEBENEFITPLANS" xlink:type="extended" id="i33c1273f919749788eb21a35de3d344e_EMPLOYEEBENEFITPLANS"/>
  <link:roleRef roleURI="http://wabtec.com/role/EMPLOYEEBENEFITPLANSTables" xlink:type="simple" xlink:href="wab-20201231.xsd#EMPLOYEEBENEFITPLANSTables"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/EMPLOYEEBENEFITPLANSTables" xlink:type="extended" id="i506ce7ce10d94b11935cfe6be383ea96_EMPLOYEEBENEFITPLANSTables">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_3cb95040-48ef-4aa9-8cfb-80b8fdc4775c" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTextBlock_4fc16d03-2990-4265-95e1-86a4759aba7b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTextBlock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_3cb95040-48ef-4aa9-8cfb-80b8fdc4775c" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTextBlock_4fc16d03-2990-4265-95e1-86a4759aba7b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAccumulatedBenefitObligationsInExcessOfFairValueOfPlanAssetsTableTextBlock_bfb905de-d336-419c-92ef-a4f527aa6c17" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfAccumulatedBenefitObligationsInExcessOfFairValueOfPlanAssetsTableTextBlock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_3cb95040-48ef-4aa9-8cfb-80b8fdc4775c" xlink:to="loc_us-gaap_ScheduleOfAccumulatedBenefitObligationsInExcessOfFairValueOfPlanAssetsTableTextBlock_bfb905de-d336-419c-92ef-a4f527aa6c17" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfNetBenefitCostsTableTextBlock_cc124e95-531f-4512-b788-c72312bb3826" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfNetBenefitCostsTableTextBlock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_3cb95040-48ef-4aa9-8cfb-80b8fdc4775c" xlink:to="loc_us-gaap_ScheduleOfNetBenefitCostsTableTextBlock_cc124e95-531f-4512-b788-c72312bb3826" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlanAmountsRecognizedInOtherComprehensiveIncomeLossTableTextBlock_8d8bfc6e-725b-4b3c-9245-b7ebdfe940ac" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfDefinedBenefitPlanAmountsRecognizedInOtherComprehensiveIncomeLossTableTextBlock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_3cb95040-48ef-4aa9-8cfb-80b8fdc4775c" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlanAmountsRecognizedInOtherComprehensiveIncomeLossTableTextBlock_8d8bfc6e-725b-4b3c-9245-b7ebdfe940ac" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAssumptionsUsedTableTextBlock_b799c61a-c176-4d69-9a73-e07eed7188d4" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfAssumptionsUsedTableTextBlock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_3cb95040-48ef-4aa9-8cfb-80b8fdc4775c" xlink:to="loc_us-gaap_ScheduleOfAssumptionsUsedTableTextBlock_b799c61a-c176-4d69-9a73-e07eed7188d4" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAmountsRecognizedInOtherComprehensiveIncomeLossTableTextBlock_f9ba7918-e82a-469c-9b76-ea82140a6afc" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfAmountsRecognizedInOtherComprehensiveIncomeLossTableTextBlock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_3cb95040-48ef-4aa9-8cfb-80b8fdc4775c" xlink:to="loc_us-gaap_ScheduleOfAmountsRecognizedInOtherComprehensiveIncomeLossTableTextBlock_f9ba7918-e82a-469c-9b76-ea82140a6afc" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAllocationOfPlanAssetsTableTextBlock_96c0c3f5-eb1d-4f86-9352-5cad570c95f5" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfAllocationOfPlanAssetsTableTextBlock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_3cb95040-48ef-4aa9-8cfb-80b8fdc4775c" xlink:to="loc_us-gaap_ScheduleOfAllocationOfPlanAssetsTableTextBlock_96c0c3f5-eb1d-4f86-9352-5cad570c95f5" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfChangesInFairValueOfPlanAssetsTableTextBlock_cc929b0d-b99c-48e5-b1c5-22f80b75fda9" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfChangesInFairValueOfPlanAssetsTableTextBlock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_3cb95040-48ef-4aa9-8cfb-80b8fdc4775c" xlink:to="loc_us-gaap_ScheduleOfChangesInFairValueOfPlanAssetsTableTextBlock_cc929b0d-b99c-48e5-b1c5-22f80b75fda9" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEffectOfSignificantUnobservableInputsChangesInPlanAssetsTableTextBlock_575481a7-e1b7-4479-bb5b-fa45c962be5a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfEffectOfSignificantUnobservableInputsChangesInPlanAssetsTableTextBlock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_3cb95040-48ef-4aa9-8cfb-80b8fdc4775c" xlink:to="loc_us-gaap_ScheduleOfEffectOfSignificantUnobservableInputsChangesInPlanAssetsTableTextBlock_575481a7-e1b7-4479-bb5b-fa45c962be5a" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfExpectedBenefitPaymentsTableTextBlock_6e89ecc8-bef1-4b94-b0af-2a3455ade2a8" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfExpectedBenefitPaymentsTableTextBlock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_3cb95040-48ef-4aa9-8cfb-80b8fdc4775c" xlink:to="loc_us-gaap_ScheduleOfExpectedBenefitPaymentsTableTextBlock_6e89ecc8-bef1-4b94-b0af-2a3455ade2a8" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_ScheduleOfDefinedContributionPlansAndMultiemployerPensionPlansTableTableTextBlock_ab466b3f-e076-4bfb-8130-34ad997eb0ed" xlink:href="wab-20201231.xsd#wab_ScheduleOfDefinedContributionPlansAndMultiemployerPensionPlansTableTableTextBlock"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_3cb95040-48ef-4aa9-8cfb-80b8fdc4775c" xlink:to="loc_wab_ScheduleOfDefinedContributionPlansAndMultiemployerPensionPlansTableTableTextBlock_ab466b3f-e076-4bfb-8130-34ad997eb0ed" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_0e7e984e-1aa3-4f70-9a78-bd395251fb57" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_3cb95040-48ef-4aa9-8cfb-80b8fdc4775c" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_0e7e984e-1aa3-4f70-9a78-bd395251fb57" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_fb7755de-c3af-47b4-a16b-e0bf4d4a689b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_0e7e984e-1aa3-4f70-9a78-bd395251fb57" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_fb7755de-c3af-47b4-a16b-e0bf4d4a689b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_fb7755de-c3af-47b4-a16b-e0bf4d4a689b_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_fb7755de-c3af-47b4-a16b-e0bf4d4a689b" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_fb7755de-c3af-47b4-a16b-e0bf4d4a689b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_b6071688-0154-4b41-ac28-deb86089840f" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_fb7755de-c3af-47b4-a16b-e0bf4d4a689b" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_b6071688-0154-4b41-ac28-deb86089840f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionPlansDefinedBenefitMember_88e75b58-d50b-4ba9-8640-cc2d2738ac14" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PensionPlansDefinedBenefitMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_b6071688-0154-4b41-ac28-deb86089840f" xlink:to="loc_us-gaap_PensionPlansDefinedBenefitMember_88e75b58-d50b-4ba9-8640-cc2d2738ac14" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/EMPLOYEEBENEFITPLANSObligationsandFundedStatusDetails" xlink:type="simple" xlink:href="wab-20201231.xsd#EMPLOYEEBENEFITPLANSObligationsandFundedStatusDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/EMPLOYEEBENEFITPLANSObligationsandFundedStatusDetails" xlink:type="extended" id="ica6abcc7951f434d84dd255a96344368_EMPLOYEEBENEFITPLANSObligationsandFundedStatusDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_01e6b304-10f7-4e7f-8669-41f3dac85d29" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_68d700b2-bbcd-4817-a41f-13d31604e528" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_01e6b304-10f7-4e7f-8669-41f3dac85d29" xlink:to="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_68d700b2-bbcd-4817-a41f-13d31604e528" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanBenefitObligation_8b5644c3-1419-4bd6-81b6-b71840e9b294" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanBenefitObligation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_68d700b2-bbcd-4817-a41f-13d31604e528" xlink:to="loc_us-gaap_DefinedBenefitPlanBenefitObligation_8b5644c3-1419-4bd6-81b6-b71840e9b294" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanServiceCost_1cfc3147-b568-49ec-8b0d-7015192e6d92" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanServiceCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_68d700b2-bbcd-4817-a41f-13d31604e528" xlink:to="loc_us-gaap_DefinedBenefitPlanServiceCost_1cfc3147-b568-49ec-8b0d-7015192e6d92" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanInterestCost_3feaa16a-ad7a-445f-8149-cf9bf4cbd727" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanInterestCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_68d700b2-bbcd-4817-a41f-13d31604e528" xlink:to="loc_us-gaap_DefinedBenefitPlanInterestCost_3feaa16a-ad7a-445f-8149-cf9bf4cbd727" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanBenefitObligationContributionsByPlanParticipant_d0e228b3-1ff2-496c-bc56-caa5ab3412e4" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanBenefitObligationContributionsByPlanParticipant"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_68d700b2-bbcd-4817-a41f-13d31604e528" xlink:to="loc_us-gaap_DefinedBenefitPlanBenefitObligationContributionsByPlanParticipant_d0e228b3-1ff2-496c-bc56-caa5ab3412e4" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_DefinedBenefitPlanCurtailmentsAndAmendments_a5fb7809-7365-462a-b6d5-08de1fcb1b6d" xlink:href="wab-20201231.xsd#wab_DefinedBenefitPlanCurtailmentsAndAmendments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_68d700b2-bbcd-4817-a41f-13d31604e528" xlink:to="loc_wab_DefinedBenefitPlanCurtailmentsAndAmendments_a5fb7809-7365-462a-b6d5-08de1fcb1b6d" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanBenefitObligationBenefitsPaid_e6b88452-71d3-4f73-8c81-4ccf76e9b02a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanBenefitObligationBenefitsPaid"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_68d700b2-bbcd-4817-a41f-13d31604e528" xlink:to="loc_us-gaap_DefinedBenefitPlanBenefitObligationBenefitsPaid_e6b88452-71d3-4f73-8c81-4ccf76e9b02a" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanBusinessCombinationsAndAcquisitionsBenefitObligation_36551bcb-4f85-46ca-951e-6ffee71282b9" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanBusinessCombinationsAndAcquisitionsBenefitObligation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_68d700b2-bbcd-4817-a41f-13d31604e528" xlink:to="loc_us-gaap_DefinedBenefitPlanBusinessCombinationsAndAcquisitionsBenefitObligation_36551bcb-4f85-46ca-951e-6ffee71282b9" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanActuarialGainLoss_847c2573-502a-4de5-9170-5cf514d8b6a8" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanActuarialGainLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_68d700b2-bbcd-4817-a41f-13d31604e528" xlink:to="loc_us-gaap_DefinedBenefitPlanActuarialGainLoss_847c2573-502a-4de5-9170-5cf514d8b6a8" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanForeignCurrencyExchangeRateChangesBenefitObligation_086d573d-c82c-4082-aecb-410ea253219b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanForeignCurrencyExchangeRateChangesBenefitObligation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_68d700b2-bbcd-4817-a41f-13d31604e528" xlink:to="loc_us-gaap_DefinedBenefitPlanForeignCurrencyExchangeRateChangesBenefitObligation_086d573d-c82c-4082-aecb-410ea253219b" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanBenefitObligation_bc8da086-8b3c-4cb1-8832-a0067783ac1e" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanBenefitObligation"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward_a7e43a3e-d413-4934-ae0a-23f42955a388" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_01e6b304-10f7-4e7f-8669-41f3dac85d29" xlink:to="loc_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward_a7e43a3e-d413-4934-ae0a-23f42955a388" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_4d480f06-a316-41c0-9310-2857fb6bb6a4" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanFairValueOfPlanAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward_a7e43a3e-d413-4934-ae0a-23f42955a388" xlink:to="loc_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_4d480f06-a316-41c0-9310-2857fb6bb6a4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanActualReturnOnPlanAssets_94af3219-f4dd-4e8d-a191-1fe5a85c921a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanActualReturnOnPlanAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward_a7e43a3e-d413-4934-ae0a-23f42955a388" xlink:to="loc_us-gaap_DefinedBenefitPlanActualReturnOnPlanAssets_94af3219-f4dd-4e8d-a191-1fe5a85c921a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanContributionsByEmployer_bafc825e-b73a-47e9-ab98-23e7f7f3c0b0" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanContributionsByEmployer"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward_a7e43a3e-d413-4934-ae0a-23f42955a388" xlink:to="loc_us-gaap_DefinedBenefitPlanContributionsByEmployer_bafc825e-b73a-47e9-ab98-23e7f7f3c0b0" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanPlanAssetsContributionsByPlanParticipant_a974ccdc-9941-4057-8faf-0f3007c97352" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanPlanAssetsContributionsByPlanParticipant"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward_a7e43a3e-d413-4934-ae0a-23f42955a388" xlink:to="loc_us-gaap_DefinedBenefitPlanPlanAssetsContributionsByPlanParticipant_a974ccdc-9941-4057-8faf-0f3007c97352" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanPlanAssetsBenefitsPaid_5fc116c5-24fa-47e6-a950-026a290f648b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanPlanAssetsBenefitsPaid"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward_a7e43a3e-d413-4934-ae0a-23f42955a388" xlink:to="loc_us-gaap_DefinedBenefitPlanPlanAssetsBenefitsPaid_5fc116c5-24fa-47e6-a950-026a290f648b" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanSettlementsPlanAssets_607b59b4-33dc-4837-8ad5-bec4934557cf" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanSettlementsPlanAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward_a7e43a3e-d413-4934-ae0a-23f42955a388" xlink:to="loc_us-gaap_DefinedBenefitPlanSettlementsPlanAssets_607b59b4-33dc-4837-8ad5-bec4934557cf" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanBusinessCombinationsAndAcquisitionsPlanAssets_5e728c3b-3af4-4d0f-94e9-2d119b94753f" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanBusinessCombinationsAndAcquisitionsPlanAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward_a7e43a3e-d413-4934-ae0a-23f42955a388" xlink:to="loc_us-gaap_DefinedBenefitPlanBusinessCombinationsAndAcquisitionsPlanAssets_5e728c3b-3af4-4d0f-94e9-2d119b94753f" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_DefinedBenefitPlanPlanAssetsOther_2537a994-4fbd-423a-b62e-0fadf7ed311e" xlink:href="wab-20201231.xsd#wab_DefinedBenefitPlanPlanAssetsOther"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward_a7e43a3e-d413-4934-ae0a-23f42955a388" xlink:to="loc_wab_DefinedBenefitPlanPlanAssetsOther_2537a994-4fbd-423a-b62e-0fadf7ed311e" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanPlanAssetsForeignCurrencyTranslationGainLoss_516996e3-fff1-4e26-b345-4948b33157a9" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanPlanAssetsForeignCurrencyTranslationGainLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward_a7e43a3e-d413-4934-ae0a-23f42955a388" xlink:to="loc_us-gaap_DefinedBenefitPlanPlanAssetsForeignCurrencyTranslationGainLoss_516996e3-fff1-4e26-b345-4948b33157a9" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_a7de9bb1-2bcf-4921-8893-e10b0b927ddf" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanFairValueOfPlanAssets"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_d70f9449-8bd4-4a12-9c80-ef56de7209e7" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanFairValueOfPlanAssets"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanBenefitObligation_2dd6d340-7492-4d70-bf97-f6233da722dd" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanBenefitObligation"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanFundedStatusOfPlan_e60d314c-1a19-47a5-b8e3-8fee6ad2c10e" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanFundedStatusOfPlan"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_01e6b304-10f7-4e7f-8669-41f3dac85d29" xlink:to="loc_us-gaap_DefinedBenefitPlanFundedStatusOfPlan_e60d314c-1a19-47a5-b8e3-8fee6ad2c10e" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAmountsRecognizedInBalanceSheetAbstract_0e07242b-ebc7-45a4-948f-96fda6036af3" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanAmountsRecognizedInBalanceSheetAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_01e6b304-10f7-4e7f-8669-41f3dac85d29" xlink:to="loc_us-gaap_DefinedBenefitPlanAmountsRecognizedInBalanceSheetAbstract_0e07242b-ebc7-45a4-948f-96fda6036af3" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAssetsForPlanBenefitsNoncurrent_98669185-ad0f-4d47-a45a-cebf0c3a12db" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanAssetsForPlanBenefitsNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanAmountsRecognizedInBalanceSheetAbstract_0e07242b-ebc7-45a4-948f-96fda6036af3" xlink:to="loc_us-gaap_DefinedBenefitPlanAssetsForPlanBenefitsNoncurrent_98669185-ad0f-4d47-a45a-cebf0c3a12db" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansCurrentLiabilities_67851d5c-28bb-47ac-af83-14d63ffc0443" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansCurrentLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanAmountsRecognizedInBalanceSheetAbstract_0e07242b-ebc7-45a4-948f-96fda6036af3" xlink:to="loc_us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansCurrentLiabilities_67851d5c-28bb-47ac-af83-14d63ffc0443" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent_66ac58f9-6f1e-452d-97f7-2252d881b2d9" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanAmountsRecognizedInBalanceSheetAbstract_0e07242b-ebc7-45a4-948f-96fda6036af3" xlink:to="loc_us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent_66ac58f9-6f1e-452d-97f7-2252d881b2d9" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAmountsRecognizedInBalanceSheet_c57d15b4-be7c-4204-9d27-11aec420165c" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanAmountsRecognizedInBalanceSheet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanAmountsRecognizedInBalanceSheetAbstract_0e07242b-ebc7-45a4-948f-96fda6036af3" xlink:to="loc_us-gaap_DefinedBenefitPlanAmountsRecognizedInBalanceSheet_c57d15b4-be7c-4204-9d27-11aec420165c" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAmountsRecognizedInOtherComprehensiveIncomeAbstract_589bc2ae-edd7-492b-b608-64686d0ca6ca" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanAmountsRecognizedInOtherComprehensiveIncomeAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_01e6b304-10f7-4e7f-8669-41f3dac85d29" xlink:to="loc_us-gaap_DefinedBenefitPlanAmountsRecognizedInOtherComprehensiveIncomeAbstract_589bc2ae-edd7-492b-b608-64686d0ca6ca" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetPriorServiceCostCreditBeforeTax_bf27d581-ffdc-47bc-8527-625e716bd0f2" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetPriorServiceCostCreditBeforeTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanAmountsRecognizedInOtherComprehensiveIncomeAbstract_589bc2ae-edd7-492b-b608-64686d0ca6ca" xlink:to="loc_us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetPriorServiceCostCreditBeforeTax_bf27d581-ffdc-47bc-8527-625e716bd0f2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesBeforeTax_3fdf48c5-32f9-40fd-ba07-26cd60a50467" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesBeforeTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanAmountsRecognizedInOtherComprehensiveIncomeAbstract_589bc2ae-edd7-492b-b608-64686d0ca6ca" xlink:to="loc_us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesBeforeTax_3fdf48c5-32f9-40fd-ba07-26cd60a50467" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeBeforeTax_4cf705d3-47dc-4048-b1f2-57e2bcc9a798" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeBeforeTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanAmountsRecognizedInOtherComprehensiveIncomeAbstract_589bc2ae-edd7-492b-b608-64686d0ca6ca" xlink:to="loc_us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeBeforeTax_4cf705d3-47dc-4048-b1f2-57e2bcc9a798" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_7db23ba5-277f-4914-96da-fac81eed5870" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_01e6b304-10f7-4e7f-8669-41f3dac85d29" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_7db23ba5-277f-4914-96da-fac81eed5870" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationAxis_ae7edef9-bbfc-467d-8a25-281432591c42" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanSponsorLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_7db23ba5-277f-4914-96da-fac81eed5870" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationAxis_ae7edef9-bbfc-467d-8a25-281432591c42" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_ae7edef9-bbfc-467d-8a25-281432591c42_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_ae7edef9-bbfc-467d-8a25-281432591c42" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_ae7edef9-bbfc-467d-8a25-281432591c42_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_a5e01e16-a045-4343-b5bb-4c6e54766926" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_ae7edef9-bbfc-467d-8a25-281432591c42" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_a5e01e16-a045-4343-b5bb-4c6e54766926" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DomesticPlanMember_0b4e1461-fbf7-4529-979a-52fae2d2962f" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DomesticPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_a5e01e16-a045-4343-b5bb-4c6e54766926" xlink:to="loc_us-gaap_DomesticPlanMember_0b4e1461-fbf7-4529-979a-52fae2d2962f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_US_8ffe8a66-62b2-435c-aa0e-32856750dc5a" xlink:href="https://xbrl.sec.gov/country/2020/country-2020-01-31.xsd#country_US"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DomesticPlanMember_0b4e1461-fbf7-4529-979a-52fae2d2962f" xlink:to="loc_country_US_8ffe8a66-62b2-435c-aa0e-32856750dc5a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignPlanMember_5495de03-028e-4bb0-8de1-387255765912" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ForeignPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_a5e01e16-a045-4343-b5bb-4c6e54766926" xlink:to="loc_us-gaap_ForeignPlanMember_5495de03-028e-4bb0-8de1-387255765912" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_507e795a-746c-4c12-92b6-d85cda17fc70" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_7db23ba5-277f-4914-96da-fac81eed5870" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_507e795a-746c-4c12-92b6-d85cda17fc70" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_507e795a-746c-4c12-92b6-d85cda17fc70_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_507e795a-746c-4c12-92b6-d85cda17fc70" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_507e795a-746c-4c12-92b6-d85cda17fc70_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_eccad371-ac7e-4f53-932b-cf7cdc050c62" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_507e795a-746c-4c12-92b6-d85cda17fc70" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_eccad371-ac7e-4f53-932b-cf7cdc050c62" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionPlansDefinedBenefitMember_a463e09e-8cae-4ef4-b191-f756c5c3fbe2" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PensionPlansDefinedBenefitMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_eccad371-ac7e-4f53-932b-cf7cdc050c62" xlink:to="loc_us-gaap_PensionPlansDefinedBenefitMember_a463e09e-8cae-4ef4-b191-f756c5c3fbe2" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/EMPLOYEEBENEFITPLANSNarrativeDetails" xlink:type="simple" xlink:href="wab-20201231.xsd#EMPLOYEEBENEFITPLANSNarrativeDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/EMPLOYEEBENEFITPLANSNarrativeDetails" xlink:type="extended" id="i76593af03f574013a5a4080cdfb48ade_EMPLOYEEBENEFITPLANSNarrativeDetails">
    <link:loc xlink:type="locator" xlink:label="loc_wab_DefinedBenefitPlansAndOtherPostretirementBenefitPlansLineItems_8c114988-6664-4384-8c43-1621a9ecdbe8" xlink:href="wab-20201231.xsd#wab_DefinedBenefitPlansAndOtherPostretirementBenefitPlansLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAccumulatedBenefitObligation_2da66ecc-91c5-4911-9f18-0abf31936740" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanAccumulatedBenefitObligation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_wab_DefinedBenefitPlansAndOtherPostretirementBenefitPlansLineItems_8c114988-6664-4384-8c43-1621a9ecdbe8" xlink:to="loc_us-gaap_DefinedBenefitPlanAccumulatedBenefitObligation_2da66ecc-91c5-4911-9f18-0abf31936740" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanPlanAssetsTargetAllocationPercentage_972bc028-94a4-46af-87a7-3c700fa3a3cd" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanPlanAssetsTargetAllocationPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_wab_DefinedBenefitPlansAndOtherPostretirementBenefitPlansLineItems_8c114988-6664-4384-8c43-1621a9ecdbe8" xlink:to="loc_us-gaap_DefinedBenefitPlanPlanAssetsTargetAllocationPercentage_972bc028-94a4-46af-87a7-3c700fa3a3cd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedFutureEmployerContributionsNextFiscalYear_c81254c1-dc65-4597-b23c-22b5eb107a93" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedFutureEmployerContributionsNextFiscalYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_wab_DefinedBenefitPlansAndOtherPostretirementBenefitPlansLineItems_8c114988-6664-4384-8c43-1621a9ecdbe8" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedFutureEmployerContributionsNextFiscalYear_c81254c1-dc65-4597-b23c-22b5eb107a93" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_DefinedContributionPlanNumberOfSharesHeldOnBehalfOfParticipants_752d4edf-9819-4e2f-95cb-7c263c8c3e65" xlink:href="wab-20201231.xsd#wab_DefinedContributionPlanNumberOfSharesHeldOnBehalfOfParticipants"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_wab_DefinedBenefitPlansAndOtherPostretirementBenefitPlansLineItems_8c114988-6664-4384-8c43-1621a9ecdbe8" xlink:to="loc_wab_DefinedContributionPlanNumberOfSharesHeldOnBehalfOfParticipants_752d4edf-9819-4e2f-95cb-7c263c8c3e65" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_DefinedContributionPlanMarketValueOfSharesHeldOnBehalfOfParticipants_233ffeef-d301-41ab-a357-c7b15b6d987e" xlink:href="wab-20201231.xsd#wab_DefinedContributionPlanMarketValueOfSharesHeldOnBehalfOfParticipants"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_wab_DefinedBenefitPlansAndOtherPostretirementBenefitPlansLineItems_8c114988-6664-4384-8c43-1621a9ecdbe8" xlink:to="loc_wab_DefinedContributionPlanMarketValueOfSharesHeldOnBehalfOfParticipants_233ffeef-d301-41ab-a357-c7b15b6d987e" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTable_7d361b44-95dc-46f1-9542-9f5045d380fb" xlink:href="wab-20201231.xsd#wab_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_wab_DefinedBenefitPlansAndOtherPostretirementBenefitPlansLineItems_8c114988-6664-4384-8c43-1621a9ecdbe8" xlink:to="loc_wab_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTable_7d361b44-95dc-46f1-9542-9f5045d380fb" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationAxis_4270feb0-87b9-40ff-876b-91e79f00f807" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanSponsorLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_wab_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTable_7d361b44-95dc-46f1-9542-9f5045d380fb" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationAxis_4270feb0-87b9-40ff-876b-91e79f00f807" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_4270feb0-87b9-40ff-876b-91e79f00f807_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_4270feb0-87b9-40ff-876b-91e79f00f807" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_4270feb0-87b9-40ff-876b-91e79f00f807_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_51831e96-6ae6-4765-b694-95a4c6b84333" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_4270feb0-87b9-40ff-876b-91e79f00f807" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_51831e96-6ae6-4765-b694-95a4c6b84333" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DomesticPlanMember_91f5b3b3-f06b-4f2f-b48c-35ccfdedd229" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DomesticPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_51831e96-6ae6-4765-b694-95a4c6b84333" xlink:to="loc_us-gaap_DomesticPlanMember_91f5b3b3-f06b-4f2f-b48c-35ccfdedd229" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_US_7a10d19d-94b5-4d41-b581-59fba979b8f8" xlink:href="https://xbrl.sec.gov/country/2020/country-2020-01-31.xsd#country_US"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DomesticPlanMember_91f5b3b3-f06b-4f2f-b48c-35ccfdedd229" xlink:to="loc_country_US_7a10d19d-94b5-4d41-b581-59fba979b8f8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignPlanMember_3075eb72-3787-4468-8423-76750126b9b2" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ForeignPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_51831e96-6ae6-4765-b694-95a4c6b84333" xlink:to="loc_us-gaap_ForeignPlanMember_3075eb72-3787-4468-8423-76750126b9b2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_283de705-1772-4ff0-9bdf-f33067bc71b5" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_wab_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTable_7d361b44-95dc-46f1-9542-9f5045d380fb" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_283de705-1772-4ff0-9bdf-f33067bc71b5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_283de705-1772-4ff0-9bdf-f33067bc71b5_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_283de705-1772-4ff0-9bdf-f33067bc71b5" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_283de705-1772-4ff0-9bdf-f33067bc71b5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_ab06466a-ee07-40e1-ab93-af68eaafef1b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_283de705-1772-4ff0-9bdf-f33067bc71b5" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_ab06466a-ee07-40e1-ab93-af68eaafef1b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionPlansDefinedBenefitMember_406cc99d-10b5-44e1-8d82-7f89f4801216" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PensionPlansDefinedBenefitMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_ab06466a-ee07-40e1-ab93-af68eaafef1b" xlink:to="loc_us-gaap_PensionPlansDefinedBenefitMember_406cc99d-10b5-44e1-8d82-7f89f4801216" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_32c7c4cf-80df-4a7b-a49f-251e345825c7" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_wab_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTable_7d361b44-95dc-46f1-9542-9f5045d380fb" xlink:to="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_32c7c4cf-80df-4a7b-a49f-251e345825c7" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanAssetCategoriesDomain_32c7c4cf-80df-4a7b-a49f-251e345825c7_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PlanAssetCategoriesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_32c7c4cf-80df-4a7b-a49f-251e345825c7" xlink:to="loc_us-gaap_PlanAssetCategoriesDomain_32c7c4cf-80df-4a7b-a49f-251e345825c7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanAssetCategoriesDomain_102bc4b6-8c8d-42c0-854b-d155d219e804" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PlanAssetCategoriesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_32c7c4cf-80df-4a7b-a49f-251e345825c7" xlink:to="loc_us-gaap_PlanAssetCategoriesDomain_102bc4b6-8c8d-42c0-854b-d155d219e804" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanEquitySecuritiesMember_ee10ef27-6333-4acf-ad2a-03fcc471b189" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanEquitySecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_102bc4b6-8c8d-42c0-854b-d155d219e804" xlink:to="loc_us-gaap_DefinedBenefitPlanEquitySecuritiesMember_ee10ef27-6333-4acf-ad2a-03fcc471b189" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanDebtSecurityMember_0396fc2c-f272-4103-844d-62ff7d77d9a9" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanDebtSecurityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_102bc4b6-8c8d-42c0-854b-d155d219e804" xlink:to="loc_us-gaap_DefinedBenefitPlanDebtSecurityMember_0396fc2c-f272-4103-844d-62ff7d77d9a9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherInvestmentsMember_3a3f6ea4-e4bc-401c-98ea-782487ec1404" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherInvestmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_102bc4b6-8c8d-42c0-854b-d155d219e804" xlink:to="loc_us-gaap_OtherInvestmentsMember_3a3f6ea4-e4bc-401c-98ea-782487ec1404" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/EMPLOYEEBENEFITPLANSScheduleofUSandInternationalPensionPlanswithAccumulatedBenefitObligationsandwithProjectedBenefitObligationsinExcessofPlanAssetsDetails" xlink:type="simple" xlink:href="wab-20201231.xsd#EMPLOYEEBENEFITPLANSScheduleofUSandInternationalPensionPlanswithAccumulatedBenefitObligationsandwithProjectedBenefitObligationsinExcessofPlanAssetsDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/EMPLOYEEBENEFITPLANSScheduleofUSandInternationalPensionPlanswithAccumulatedBenefitObligationsandwithProjectedBenefitObligationsinExcessofPlanAssetsDetails" xlink:type="extended" id="i040d7af8a59c4e708f4c846ecbca1e34_EMPLOYEEBENEFITPLANSScheduleofUSandInternationalPensionPlanswithAccumulatedBenefitObligationsandwithProjectedBenefitObligationsinExcessofPlanAssetsDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_814c59c4-9964-4e3c-ae57-beef96bc7da0" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateProjectedBenefitObligation_92701015-6a4a-4cad-8fea-3f78d460f91d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateProjectedBenefitObligation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_814c59c4-9964-4e3c-ae57-beef96bc7da0" xlink:to="loc_us-gaap_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateProjectedBenefitObligation_92701015-6a4a-4cad-8fea-3f78d460f91d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateAccumulatedBenefitObligation_4bab994d-c37b-46f7-a3af-bb0729f3ff04" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateAccumulatedBenefitObligation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_814c59c4-9964-4e3c-ae57-beef96bc7da0" xlink:to="loc_us-gaap_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateAccumulatedBenefitObligation_4bab994d-c37b-46f7-a3af-bb0729f3ff04" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateFairValueOfPlanAssets_ca451175-ce85-44a8-b991-f4425fa655c0" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateFairValueOfPlanAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_814c59c4-9964-4e3c-ae57-beef96bc7da0" xlink:to="loc_us-gaap_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateFairValueOfPlanAssets_ca451175-ce85-44a8-b991-f4425fa655c0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanPensionPlanWithProjectedBenefitObligationInExcessOfPlanAssetsProjectedBenefitObligation_4be275a6-091b-4729-aae1-12d1fd10228b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanPensionPlanWithProjectedBenefitObligationInExcessOfPlanAssetsProjectedBenefitObligation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_814c59c4-9964-4e3c-ae57-beef96bc7da0" xlink:to="loc_us-gaap_DefinedBenefitPlanPensionPlanWithProjectedBenefitObligationInExcessOfPlanAssetsProjectedBenefitObligation_4be275a6-091b-4729-aae1-12d1fd10228b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanPensionPlanWithProjectedBenefitObligationInExcessOfPlanAssetsPlanAssets_8743add3-eb30-4b6c-8829-9e77a1437b7f" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanPensionPlanWithProjectedBenefitObligationInExcessOfPlanAssetsPlanAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_814c59c4-9964-4e3c-ae57-beef96bc7da0" xlink:to="loc_us-gaap_DefinedBenefitPlanPensionPlanWithProjectedBenefitObligationInExcessOfPlanAssetsPlanAssets_8743add3-eb30-4b6c-8829-9e77a1437b7f" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_56a6095f-2269-4ca4-beb8-2a739f614df7" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_814c59c4-9964-4e3c-ae57-beef96bc7da0" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_56a6095f-2269-4ca4-beb8-2a739f614df7" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationAxis_864719cd-3b59-4e43-a336-aa24a281dc33" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanSponsorLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_56a6095f-2269-4ca4-beb8-2a739f614df7" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationAxis_864719cd-3b59-4e43-a336-aa24a281dc33" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_864719cd-3b59-4e43-a336-aa24a281dc33_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_864719cd-3b59-4e43-a336-aa24a281dc33" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_864719cd-3b59-4e43-a336-aa24a281dc33_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_e1db9603-b011-4d36-ba36-71562ca994da" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_864719cd-3b59-4e43-a336-aa24a281dc33" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_e1db9603-b011-4d36-ba36-71562ca994da" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DomesticPlanMember_020f806e-2ecc-40a1-80df-69164e951cd2" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DomesticPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_e1db9603-b011-4d36-ba36-71562ca994da" xlink:to="loc_us-gaap_DomesticPlanMember_020f806e-2ecc-40a1-80df-69164e951cd2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_US_8b534329-aadb-49e3-867e-b7bd68d0dd96" xlink:href="https://xbrl.sec.gov/country/2020/country-2020-01-31.xsd#country_US"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DomesticPlanMember_020f806e-2ecc-40a1-80df-69164e951cd2" xlink:to="loc_country_US_8b534329-aadb-49e3-867e-b7bd68d0dd96" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignPlanMember_9ff96b55-1e23-42f3-b517-5225aecab380" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ForeignPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_e1db9603-b011-4d36-ba36-71562ca994da" xlink:to="loc_us-gaap_ForeignPlanMember_9ff96b55-1e23-42f3-b517-5225aecab380" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_78b1e753-61eb-4ac7-ad3b-c4c8bd3b56d4" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_56a6095f-2269-4ca4-beb8-2a739f614df7" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_78b1e753-61eb-4ac7-ad3b-c4c8bd3b56d4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_78b1e753-61eb-4ac7-ad3b-c4c8bd3b56d4_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_78b1e753-61eb-4ac7-ad3b-c4c8bd3b56d4" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_78b1e753-61eb-4ac7-ad3b-c4c8bd3b56d4_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_de75bfa1-cf0f-4502-aac7-7cb0a491f4f8" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_78b1e753-61eb-4ac7-ad3b-c4c8bd3b56d4" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_de75bfa1-cf0f-4502-aac7-7cb0a491f4f8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionPlansDefinedBenefitMember_8306c1f3-8f30-4183-b717-9444f748a7aa" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PensionPlansDefinedBenefitMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_de75bfa1-cf0f-4502-aac7-7cb0a491f4f8" xlink:to="loc_us-gaap_PensionPlansDefinedBenefitMember_8306c1f3-8f30-4183-b717-9444f748a7aa" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/EMPLOYEEBENEFITPLANSComponentsofNetPeriodicBenefitCostsDetails" xlink:type="simple" xlink:href="wab-20201231.xsd#EMPLOYEEBENEFITPLANSComponentsofNetPeriodicBenefitCostsDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/EMPLOYEEBENEFITPLANSComponentsofNetPeriodicBenefitCostsDetails" xlink:type="extended" id="ic53f216b9205418a9dc77bbd9d164d1b_EMPLOYEEBENEFITPLANSComponentsofNetPeriodicBenefitCostsDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_7307c3d9-7b48-4109-8066-b5e2cd5a06fc" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanServiceCost_6532148e-b17c-4eb4-a6c1-04131283f5bc" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanServiceCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_7307c3d9-7b48-4109-8066-b5e2cd5a06fc" xlink:to="loc_us-gaap_DefinedBenefitPlanServiceCost_6532148e-b17c-4eb4-a6c1-04131283f5bc" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanInterestCost_c8b1fdb3-43c8-4e02-a8f6-6fbcfd8e8a53" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanInterestCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_7307c3d9-7b48-4109-8066-b5e2cd5a06fc" xlink:to="loc_us-gaap_DefinedBenefitPlanInterestCost_c8b1fdb3-43c8-4e02-a8f6-6fbcfd8e8a53" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets_6ea035b4-754c-4972-a7d6-a8d022cb6566" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_7307c3d9-7b48-4109-8066-b5e2cd5a06fc" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets_6ea035b4-754c-4972-a7d6-a8d022cb6566" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_DefinedBenefitPlanAmortizationOfTransitionObligationsAssetsAndPriorServiceCostCredit_80feb092-2d42-4ca2-b4e7-645bed4ec447" xlink:href="wab-20201231.xsd#wab_DefinedBenefitPlanAmortizationOfTransitionObligationsAssetsAndPriorServiceCostCredit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_7307c3d9-7b48-4109-8066-b5e2cd5a06fc" xlink:to="loc_wab_DefinedBenefitPlanAmortizationOfTransitionObligationsAssetsAndPriorServiceCostCredit_80feb092-2d42-4ca2-b4e7-645bed4ec447" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses_228a6675-d091-4586-bd1c-e0c0a032b8dc" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_7307c3d9-7b48-4109-8066-b5e2cd5a06fc" xlink:to="loc_us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses_228a6675-d091-4586-bd1c-e0c0a032b8dc" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanRecognizedNetGainLossDueToSettlementsAndCurtailments1_f2116719-1995-4ad6-9047-c87beddeef73" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanRecognizedNetGainLossDueToSettlementsAndCurtailments1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_7307c3d9-7b48-4109-8066-b5e2cd5a06fc" xlink:to="loc_us-gaap_DefinedBenefitPlanRecognizedNetGainLossDueToSettlementsAndCurtailments1_f2116719-1995-4ad6-9047-c87beddeef73" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost_dc52fcac-543a-40f7-8f88-f19f71a4e47d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_7307c3d9-7b48-4109-8066-b5e2cd5a06fc" xlink:to="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost_dc52fcac-543a-40f7-8f88-f19f71a4e47d" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_ba6ca423-ab14-43eb-93b9-fc72e8e57a4e" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_7307c3d9-7b48-4109-8066-b5e2cd5a06fc" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_ba6ca423-ab14-43eb-93b9-fc72e8e57a4e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationAxis_d4d29a00-d18d-4484-a3a7-3d8239de20ef" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanSponsorLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_ba6ca423-ab14-43eb-93b9-fc72e8e57a4e" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationAxis_d4d29a00-d18d-4484-a3a7-3d8239de20ef" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_d4d29a00-d18d-4484-a3a7-3d8239de20ef_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_d4d29a00-d18d-4484-a3a7-3d8239de20ef" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_d4d29a00-d18d-4484-a3a7-3d8239de20ef_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_ba8b1bd5-bed5-40df-bf4d-11893fa79909" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_d4d29a00-d18d-4484-a3a7-3d8239de20ef" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_ba8b1bd5-bed5-40df-bf4d-11893fa79909" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DomesticPlanMember_30de9106-35f5-44a7-a2f8-377f04b87d60" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DomesticPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_ba8b1bd5-bed5-40df-bf4d-11893fa79909" xlink:to="loc_us-gaap_DomesticPlanMember_30de9106-35f5-44a7-a2f8-377f04b87d60" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_US_4c9a84e0-568f-40c2-aa41-a262dee37b15" xlink:href="https://xbrl.sec.gov/country/2020/country-2020-01-31.xsd#country_US"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DomesticPlanMember_30de9106-35f5-44a7-a2f8-377f04b87d60" xlink:to="loc_country_US_4c9a84e0-568f-40c2-aa41-a262dee37b15" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignPlanMember_3132dfb1-dff7-4b8b-b071-0e8b67b8c692" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ForeignPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_ba8b1bd5-bed5-40df-bf4d-11893fa79909" xlink:to="loc_us-gaap_ForeignPlanMember_3132dfb1-dff7-4b8b-b071-0e8b67b8c692" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_17270e85-5ee4-4232-8c83-edd94a8084d9" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_ba6ca423-ab14-43eb-93b9-fc72e8e57a4e" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_17270e85-5ee4-4232-8c83-edd94a8084d9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_17270e85-5ee4-4232-8c83-edd94a8084d9_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_17270e85-5ee4-4232-8c83-edd94a8084d9" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_17270e85-5ee4-4232-8c83-edd94a8084d9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_1f26742b-c41c-4a97-a8ac-44442a7f8a6a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_17270e85-5ee4-4232-8c83-edd94a8084d9" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_1f26742b-c41c-4a97-a8ac-44442a7f8a6a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionPlansDefinedBenefitMember_af462356-ce53-484a-b77d-fcd9c0b9e17a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PensionPlansDefinedBenefitMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_1f26742b-c41c-4a97-a8ac-44442a7f8a6a" xlink:to="loc_us-gaap_PensionPlansDefinedBenefitMember_af462356-ce53-484a-b77d-fcd9c0b9e17a" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/EMPLOYEEBENEFITPLANSOtherChangesinPlanAssetsandBenefitObligationsRecognizedinOtherComprehensiveIncomeDetails" xlink:type="simple" xlink:href="wab-20201231.xsd#EMPLOYEEBENEFITPLANSOtherChangesinPlanAssetsandBenefitObligationsRecognizedinOtherComprehensiveIncomeDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/EMPLOYEEBENEFITPLANSOtherChangesinPlanAssetsandBenefitObligationsRecognizedinOtherComprehensiveIncomeDetails" xlink:type="extended" id="i379ff10745dd48348901a327e384fde8_EMPLOYEEBENEFITPLANSOtherChangesinPlanAssetsandBenefitObligationsRecognizedinOtherComprehensiveIncomeDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_16538dbe-32ff-4fc4-87d2-d0b66d4d2907" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossNetOfTax_c8c10520-6b2a-497d-a891-f03b4172f316" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_16538dbe-32ff-4fc4-87d2-d0b66d4d2907" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossNetOfTax_c8c10520-6b2a-497d-a891-f03b4172f316" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_OtherComprehensiveIncomeDefinedBenefitPlansEffectOfExchangeRates_d1d86e7c-0086-41f4-8a83-139e556adfbd" xlink:href="wab-20201231.xsd#wab_OtherComprehensiveIncomeDefinedBenefitPlansEffectOfExchangeRates"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_16538dbe-32ff-4fc4-87d2-d0b66d4d2907" xlink:to="loc_wab_OtherComprehensiveIncomeDefinedBenefitPlansEffectOfExchangeRates_d1d86e7c-0086-41f4-8a83-139e556adfbd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditNetOfTax_41f9b2a8-0655-4e76-872f-2e0dd7bf8cb4" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_16538dbe-32ff-4fc4-87d2-d0b66d4d2907" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossAmortizationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetPriorServiceCostCreditNetOfTax_41f9b2a8-0655-4e76-872f-2e0dd7bf8cb4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_OtherComprehensiveIncomeDefinedBenefitPlansAmortizationOrSettlementRecognitionOfNetLossGain_5c3bfcac-4240-49e6-b451-52b4a16f1104" xlink:href="wab-20201231.xsd#wab_OtherComprehensiveIncomeDefinedBenefitPlansAmortizationOrSettlementRecognitionOfNetLossGain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_16538dbe-32ff-4fc4-87d2-d0b66d4d2907" xlink:to="loc_wab_OtherComprehensiveIncomeDefinedBenefitPlansAmortizationOrSettlementRecognitionOfNetLossGain_5c3bfcac-4240-49e6-b451-52b4a16f1104" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAmountsRecognizedInOtherComprehensiveIncomeLossNetGainLossBeforeTax_f54b4fda-5839-416d-93c5-2f0549d188b1" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanAmountsRecognizedInOtherComprehensiveIncomeLossNetGainLossBeforeTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_16538dbe-32ff-4fc4-87d2-d0b66d4d2907" xlink:to="loc_us-gaap_DefinedBenefitPlanAmountsRecognizedInOtherComprehensiveIncomeLossNetGainLossBeforeTax_f54b4fda-5839-416d-93c5-2f0549d188b1" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeDefinedBenefitPlansAdjustmentNetOfTaxPortionAttributableToParent_4d9129d3-8175-4f25-b777-81bd095bd4bc" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeDefinedBenefitPlansAdjustmentNetOfTaxPortionAttributableToParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_16538dbe-32ff-4fc4-87d2-d0b66d4d2907" xlink:to="loc_us-gaap_OtherComprehensiveIncomeDefinedBenefitPlansAdjustmentNetOfTaxPortionAttributableToParent_4d9129d3-8175-4f25-b777-81bd095bd4bc" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_12bf3686-9e7d-408d-a63a-19dacdd93a71" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_16538dbe-32ff-4fc4-87d2-d0b66d4d2907" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_12bf3686-9e7d-408d-a63a-19dacdd93a71" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationAxis_8e88f579-c9de-4878-bf4b-d5309dbba3af" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanSponsorLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_12bf3686-9e7d-408d-a63a-19dacdd93a71" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationAxis_8e88f579-c9de-4878-bf4b-d5309dbba3af" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_8e88f579-c9de-4878-bf4b-d5309dbba3af_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_8e88f579-c9de-4878-bf4b-d5309dbba3af" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_8e88f579-c9de-4878-bf4b-d5309dbba3af_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_6e30df44-3c0f-4ed1-b2e3-b6e6cba49fcc" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_8e88f579-c9de-4878-bf4b-d5309dbba3af" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_6e30df44-3c0f-4ed1-b2e3-b6e6cba49fcc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DomesticPlanMember_a32ab8fa-175e-4edf-9c7d-02caee457c06" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DomesticPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_6e30df44-3c0f-4ed1-b2e3-b6e6cba49fcc" xlink:to="loc_us-gaap_DomesticPlanMember_a32ab8fa-175e-4edf-9c7d-02caee457c06" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_US_4cc7e242-6cd3-4b4d-9fb6-34fe4d444343" xlink:href="https://xbrl.sec.gov/country/2020/country-2020-01-31.xsd#country_US"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DomesticPlanMember_a32ab8fa-175e-4edf-9c7d-02caee457c06" xlink:to="loc_country_US_4cc7e242-6cd3-4b4d-9fb6-34fe4d444343" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignPlanMember_6dd33298-3618-4ab2-928c-53db026ad713" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ForeignPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_6e30df44-3c0f-4ed1-b2e3-b6e6cba49fcc" xlink:to="loc_us-gaap_ForeignPlanMember_6dd33298-3618-4ab2-928c-53db026ad713" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_fb487218-1461-4af2-abcc-a613b5512481" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_12bf3686-9e7d-408d-a63a-19dacdd93a71" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_fb487218-1461-4af2-abcc-a613b5512481" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_fb487218-1461-4af2-abcc-a613b5512481_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_fb487218-1461-4af2-abcc-a613b5512481" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_fb487218-1461-4af2-abcc-a613b5512481_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_46dac905-ec3f-4521-9770-73b7d3dcb010" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_fb487218-1461-4af2-abcc-a613b5512481" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_46dac905-ec3f-4521-9770-73b7d3dcb010" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionPlansDefinedBenefitMember_8c97d017-ca14-4b29-935c-5516909a8a2e" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PensionPlansDefinedBenefitMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_46dac905-ec3f-4521-9770-73b7d3dcb010" xlink:to="loc_us-gaap_PensionPlansDefinedBenefitMember_8c97d017-ca14-4b29-935c-5516909a8a2e" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/EMPLOYEEBENEFITPLANSWeightedAverageAssumptionsUsedtoDevelopActuarialPresentValueofProjectedBenefitObligationDetails" xlink:type="simple" xlink:href="wab-20201231.xsd#EMPLOYEEBENEFITPLANSWeightedAverageAssumptionsUsedtoDevelopActuarialPresentValueofProjectedBenefitObligationDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/EMPLOYEEBENEFITPLANSWeightedAverageAssumptionsUsedtoDevelopActuarialPresentValueofProjectedBenefitObligationDetails" xlink:type="extended" id="ia3c6247cee1b4086ae1ed649fccec31b_EMPLOYEEBENEFITPLANSWeightedAverageAssumptionsUsedtoDevelopActuarialPresentValueofProjectedBenefitObligationDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_fbb505f2-d0c0-42bb-981d-90d670c69339" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate_e1c5a6bb-89a9-4093-a5d5-2227a6027486" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_fbb505f2-d0c0-42bb-981d-90d670c69339" xlink:to="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate_e1c5a6bb-89a9-4093-a5d5-2227a6027486" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostExpectedLongTermReturnOnAssets_9ae75f0f-29e6-425a-ac08-9803ca5299c9" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostExpectedLongTermReturnOnAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_fbb505f2-d0c0-42bb-981d-90d670c69339" xlink:to="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostExpectedLongTermReturnOnAssets_9ae75f0f-29e6-425a-ac08-9803ca5299c9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostRateOfCompensationIncrease_1b7186c8-8bed-4e49-9f8e-8b2ca11eae2f" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostRateOfCompensationIncrease"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_fbb505f2-d0c0-42bb-981d-90d670c69339" xlink:to="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostRateOfCompensationIncrease_1b7186c8-8bed-4e49-9f8e-8b2ca11eae2f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_9c21e331-22ff-4970-abc6-ba447d16c93d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_fbb505f2-d0c0-42bb-981d-90d670c69339" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_9c21e331-22ff-4970-abc6-ba447d16c93d" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationAxis_e42a1dd8-6cdc-48a8-a1dc-568c71044b3b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanSponsorLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_9c21e331-22ff-4970-abc6-ba447d16c93d" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationAxis_e42a1dd8-6cdc-48a8-a1dc-568c71044b3b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_e42a1dd8-6cdc-48a8-a1dc-568c71044b3b_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_e42a1dd8-6cdc-48a8-a1dc-568c71044b3b" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_e42a1dd8-6cdc-48a8-a1dc-568c71044b3b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_62980379-ea55-4343-98cb-bedd51dd3e17" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_e42a1dd8-6cdc-48a8-a1dc-568c71044b3b" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_62980379-ea55-4343-98cb-bedd51dd3e17" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DomesticPlanMember_3ed26710-df85-4c0d-a128-0335b1094805" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DomesticPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_62980379-ea55-4343-98cb-bedd51dd3e17" xlink:to="loc_us-gaap_DomesticPlanMember_3ed26710-df85-4c0d-a128-0335b1094805" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_US_20028ee0-a038-4a61-90e2-47e8f75fe5a7" xlink:href="https://xbrl.sec.gov/country/2020/country-2020-01-31.xsd#country_US"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DomesticPlanMember_3ed26710-df85-4c0d-a128-0335b1094805" xlink:to="loc_country_US_20028ee0-a038-4a61-90e2-47e8f75fe5a7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignPlanMember_30c8e276-201b-4b50-be68-f09efc5ebe92" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ForeignPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_62980379-ea55-4343-98cb-bedd51dd3e17" xlink:to="loc_us-gaap_ForeignPlanMember_30c8e276-201b-4b50-be68-f09efc5ebe92" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_59856b07-718d-4784-8520-c0710d553371" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_9c21e331-22ff-4970-abc6-ba447d16c93d" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_59856b07-718d-4784-8520-c0710d553371" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_59856b07-718d-4784-8520-c0710d553371_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_59856b07-718d-4784-8520-c0710d553371" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_59856b07-718d-4784-8520-c0710d553371_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_5e8aa975-b90d-4f17-9d55-15e37910830c" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_59856b07-718d-4784-8520-c0710d553371" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_5e8aa975-b90d-4f17-9d55-15e37910830c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionPlansDefinedBenefitMember_8d304181-8315-4047-99d7-c25a7cfafbbd" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PensionPlansDefinedBenefitMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_5e8aa975-b90d-4f17-9d55-15e37910830c" xlink:to="loc_us-gaap_PensionPlansDefinedBenefitMember_8d304181-8315-4047-99d7-c25a7cfafbbd" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/EMPLOYEEBENEFITPLANSAmountsIncludedinOtherComprehensiveLossThatareExpectedtobeRecognizedasComponentsofPeriodicBenefitCostsDetails" xlink:type="simple" xlink:href="wab-20201231.xsd#EMPLOYEEBENEFITPLANSAmountsIncludedinOtherComprehensiveLossThatareExpectedtobeRecognizedasComponentsofPeriodicBenefitCostsDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/EMPLOYEEBENEFITPLANSAmountsIncludedinOtherComprehensiveLossThatareExpectedtobeRecognizedasComponentsofPeriodicBenefitCostsDetails" xlink:type="extended" id="i1337879821294a79bdb9f41405c66972_EMPLOYEEBENEFITPLANSAmountsIncludedinOtherComprehensiveLossThatareExpectedtobeRecognizedasComponentsofPeriodicBenefitCostsDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_7a08976c-b842-4252-b8be-334066970cd5" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedAmortizationOfPriorServiceCostCreditNextFiscalYear_06b5ff8e-e2ce-4aab-b074-f509bbe7c6c4" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedAmortizationOfPriorServiceCostCreditNextFiscalYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_7a08976c-b842-4252-b8be-334066970cd5" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedAmortizationOfPriorServiceCostCreditNextFiscalYear_06b5ff8e-e2ce-4aab-b074-f509bbe7c6c4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedAmortizationOfGainLossNextFiscalYear_11bdbc86-e4b6-4cc6-a57c-8d5820827262" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedAmortizationOfGainLossNextFiscalYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_7a08976c-b842-4252-b8be-334066970cd5" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedAmortizationOfGainLossNextFiscalYear_11bdbc86-e4b6-4cc6-a57c-8d5820827262" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedAmortizationNextFiscalYear_3d684306-8893-402c-9372-f2481a0d81f8" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedAmortizationNextFiscalYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_7a08976c-b842-4252-b8be-334066970cd5" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedAmortizationNextFiscalYear_3d684306-8893-402c-9372-f2481a0d81f8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_9413726f-3313-4f64-b6c2-7f951118089b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_7a08976c-b842-4252-b8be-334066970cd5" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_9413726f-3313-4f64-b6c2-7f951118089b" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationAxis_1353d576-f27e-4fb8-adfd-9789c572000f" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanSponsorLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_9413726f-3313-4f64-b6c2-7f951118089b" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationAxis_1353d576-f27e-4fb8-adfd-9789c572000f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_1353d576-f27e-4fb8-adfd-9789c572000f_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_1353d576-f27e-4fb8-adfd-9789c572000f" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_1353d576-f27e-4fb8-adfd-9789c572000f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_f425b6f2-5f71-412a-95de-02ce77436d17" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_1353d576-f27e-4fb8-adfd-9789c572000f" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_f425b6f2-5f71-412a-95de-02ce77436d17" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DomesticPlanMember_40af2790-77fe-4485-8be3-cd7d1ea91fe7" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DomesticPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_f425b6f2-5f71-412a-95de-02ce77436d17" xlink:to="loc_us-gaap_DomesticPlanMember_40af2790-77fe-4485-8be3-cd7d1ea91fe7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_US_a0921966-d0a4-47c5-8320-ac7ad3a4b218" xlink:href="https://xbrl.sec.gov/country/2020/country-2020-01-31.xsd#country_US"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DomesticPlanMember_40af2790-77fe-4485-8be3-cd7d1ea91fe7" xlink:to="loc_country_US_a0921966-d0a4-47c5-8320-ac7ad3a4b218" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignPlanMember_361cd1a9-38bf-4206-8e60-672b07a8898d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ForeignPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_f425b6f2-5f71-412a-95de-02ce77436d17" xlink:to="loc_us-gaap_ForeignPlanMember_361cd1a9-38bf-4206-8e60-672b07a8898d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_e27dddf2-163a-4baf-9b4a-08f61a2b73a5" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_9413726f-3313-4f64-b6c2-7f951118089b" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_e27dddf2-163a-4baf-9b4a-08f61a2b73a5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_e27dddf2-163a-4baf-9b4a-08f61a2b73a5_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_e27dddf2-163a-4baf-9b4a-08f61a2b73a5" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_e27dddf2-163a-4baf-9b4a-08f61a2b73a5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_5ec44942-e54b-4cd5-9378-81b626e74ac0" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_e27dddf2-163a-4baf-9b4a-08f61a2b73a5" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_5ec44942-e54b-4cd5-9378-81b626e74ac0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionPlansDefinedBenefitMember_45b3f28b-1f82-467c-85a2-4f9b6e3ef4b6" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PensionPlansDefinedBenefitMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_5ec44942-e54b-4cd5-9378-81b626e74ac0" xlink:to="loc_us-gaap_PensionPlansDefinedBenefitMember_45b3f28b-1f82-467c-85a2-4f9b6e3ef4b6" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/EMPLOYEEBENEFITPLANSPensionPlanAssetsbyAssetCategoryDetails" xlink:type="simple" xlink:href="wab-20201231.xsd#EMPLOYEEBENEFITPLANSPensionPlanAssetsbyAssetCategoryDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/EMPLOYEEBENEFITPLANSPensionPlanAssetsbyAssetCategoryDetails" xlink:type="extended" id="i1b5c4d16a68e43ee87b5047643a874c7_EMPLOYEEBENEFITPLANSPensionPlanAssetsbyAssetCategoryDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_8042ed33-7078-4208-8509-d5ab7dd2b69e" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_a561b666-b530-44a1-b8f5-d331efdf46d7" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanFairValueOfPlanAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_8042ed33-7078-4208-8509-d5ab7dd2b69e" xlink:to="loc_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_a561b666-b530-44a1-b8f5-d331efdf46d7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_2c0ce603-be9c-441e-bc2b-26b567d95677" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_8042ed33-7078-4208-8509-d5ab7dd2b69e" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_2c0ce603-be9c-441e-bc2b-26b567d95677" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationAxis_7076fb88-0802-44c1-8af2-e4c08698e0da" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanSponsorLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_2c0ce603-be9c-441e-bc2b-26b567d95677" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationAxis_7076fb88-0802-44c1-8af2-e4c08698e0da" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_7076fb88-0802-44c1-8af2-e4c08698e0da_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_7076fb88-0802-44c1-8af2-e4c08698e0da" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_7076fb88-0802-44c1-8af2-e4c08698e0da_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_bab083d8-e265-4481-86da-de664057fceb" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_7076fb88-0802-44c1-8af2-e4c08698e0da" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_bab083d8-e265-4481-86da-de664057fceb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DomesticPlanMember_c4c5207d-ff62-470c-ab4b-163753278809" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DomesticPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_bab083d8-e265-4481-86da-de664057fceb" xlink:to="loc_us-gaap_DomesticPlanMember_c4c5207d-ff62-470c-ab4b-163753278809" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_US_8e52a8a4-b3cb-48b8-86f0-ee5d193bffdd" xlink:href="https://xbrl.sec.gov/country/2020/country-2020-01-31.xsd#country_US"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DomesticPlanMember_c4c5207d-ff62-470c-ab4b-163753278809" xlink:to="loc_country_US_8e52a8a4-b3cb-48b8-86f0-ee5d193bffdd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignPlanMember_532d9d5f-0171-4992-95db-ce78b1ae425d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ForeignPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_bab083d8-e265-4481-86da-de664057fceb" xlink:to="loc_us-gaap_ForeignPlanMember_532d9d5f-0171-4992-95db-ce78b1ae425d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_c236b67b-d1e3-4d98-a40d-b1c3244998c5" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_2c0ce603-be9c-441e-bc2b-26b567d95677" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_c236b67b-d1e3-4d98-a40d-b1c3244998c5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_c236b67b-d1e3-4d98-a40d-b1c3244998c5_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_c236b67b-d1e3-4d98-a40d-b1c3244998c5" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_c236b67b-d1e3-4d98-a40d-b1c3244998c5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_3502e545-4980-474a-ba6f-5f5213b17dd2" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_c236b67b-d1e3-4d98-a40d-b1c3244998c5" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_3502e545-4980-474a-ba6f-5f5213b17dd2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionPlansDefinedBenefitMember_e0e6b2f3-da03-47d7-adc1-47ca66a23db7" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PensionPlansDefinedBenefitMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_3502e545-4980-474a-ba6f-5f5213b17dd2" xlink:to="loc_us-gaap_PensionPlansDefinedBenefitMember_e0e6b2f3-da03-47d7-adc1-47ca66a23db7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_12b6f79c-9116-4096-af4f-0bad18e2165a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_2c0ce603-be9c-441e-bc2b-26b567d95677" xlink:to="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_12b6f79c-9116-4096-af4f-0bad18e2165a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanAssetCategoriesDomain_12b6f79c-9116-4096-af4f-0bad18e2165a_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PlanAssetCategoriesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_12b6f79c-9116-4096-af4f-0bad18e2165a" xlink:to="loc_us-gaap_PlanAssetCategoriesDomain_12b6f79c-9116-4096-af4f-0bad18e2165a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanAssetCategoriesDomain_fc431fdc-4875-4351-8287-a53677b16322" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PlanAssetCategoriesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_12b6f79c-9116-4096-af4f-0bad18e2165a" xlink:to="loc_us-gaap_PlanAssetCategoriesDomain_fc431fdc-4875-4351-8287-a53677b16322" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanEquitySecuritiesMember_1d204139-324f-4fe6-9893-8b954e56c1c8" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanEquitySecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_fc431fdc-4875-4351-8287-a53677b16322" xlink:to="loc_us-gaap_DefinedBenefitPlanEquitySecuritiesMember_1d204139-324f-4fe6-9893-8b954e56c1c8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanDebtSecurityMember_5c58257e-46f9-43c2-9a96-aa474368eb34" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanDebtSecurityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_fc431fdc-4875-4351-8287-a53677b16322" xlink:to="loc_us-gaap_DefinedBenefitPlanDebtSecurityMember_5c58257e-46f9-43c2-9a96-aa474368eb34" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanCashAndCashEquivalentsMember_8da4d806-8ee1-42e5-a377-c19f0e8d5cfe" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanCashAndCashEquivalentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_fc431fdc-4875-4351-8287-a53677b16322" xlink:to="loc_us-gaap_DefinedBenefitPlanCashAndCashEquivalentsMember_8da4d806-8ee1-42e5-a377-c19f0e8d5cfe" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/EMPLOYEEBENEFITPLANSScheduleofPensionPlanAssetsMeasuredatFairValueDetails" xlink:type="simple" xlink:href="wab-20201231.xsd#EMPLOYEEBENEFITPLANSScheduleofPensionPlanAssetsMeasuredatFairValueDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/EMPLOYEEBENEFITPLANSScheduleofPensionPlanAssetsMeasuredatFairValueDetails" xlink:type="extended" id="i7f826d586b964e89a5fce3825e114c36_EMPLOYEEBENEFITPLANSScheduleofPensionPlanAssetsMeasuredatFairValueDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_20ec32f8-c76b-4512-94a7-35c548f745bf" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_6891a674-3290-4548-8263-9e8fda30dd00" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanFairValueOfPlanAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_20ec32f8-c76b-4512-94a7-35c548f745bf" xlink:to="loc_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_6891a674-3290-4548-8263-9e8fda30dd00" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_c48ad727-57aa-406e-a0bc-61d9115d9498" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_20ec32f8-c76b-4512-94a7-35c548f745bf" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_c48ad727-57aa-406e-a0bc-61d9115d9498" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_559cbaf1-ed33-4107-b6a5-1b2bf485e848" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_c48ad727-57aa-406e-a0bc-61d9115d9498" xlink:to="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_559cbaf1-ed33-4107-b6a5-1b2bf485e848" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanAssetCategoriesDomain_559cbaf1-ed33-4107-b6a5-1b2bf485e848_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PlanAssetCategoriesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_559cbaf1-ed33-4107-b6a5-1b2bf485e848" xlink:to="loc_us-gaap_PlanAssetCategoriesDomain_559cbaf1-ed33-4107-b6a5-1b2bf485e848_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanAssetCategoriesDomain_eb08ef9b-17db-4bd6-ba5f-9caae72dc76e" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PlanAssetCategoriesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_559cbaf1-ed33-4107-b6a5-1b2bf485e848" xlink:to="loc_us-gaap_PlanAssetCategoriesDomain_eb08ef9b-17db-4bd6-ba5f-9caae72dc76e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanEquitySecuritiesUsMember_e44f7e20-fc21-44d3-bf0e-cb9f90cd553b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanEquitySecuritiesUsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_eb08ef9b-17db-4bd6-ba5f-9caae72dc76e" xlink:to="loc_us-gaap_DefinedBenefitPlanEquitySecuritiesUsMember_e44f7e20-fc21-44d3-bf0e-cb9f90cd553b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_DefinedBenefitPlanDebtSecurityAndOtherUSMember_5eb9245d-1f35-4cda-ae00-1ad3d8249ecb" xlink:href="wab-20201231.xsd#wab_DefinedBenefitPlanDebtSecurityAndOtherUSMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_eb08ef9b-17db-4bd6-ba5f-9caae72dc76e" xlink:to="loc_wab_DefinedBenefitPlanDebtSecurityAndOtherUSMember_5eb9245d-1f35-4cda-ae00-1ad3d8249ecb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_DefinedBenefitPlanCashAndCashEquivalentsUSMember_601c8232-760d-4c95-8e41-29c46b99997d" xlink:href="wab-20201231.xsd#wab_DefinedBenefitPlanCashAndCashEquivalentsUSMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_eb08ef9b-17db-4bd6-ba5f-9caae72dc76e" xlink:to="loc_wab_DefinedBenefitPlanCashAndCashEquivalentsUSMember_601c8232-760d-4c95-8e41-29c46b99997d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanEquitySecuritiesNonUsMember_97a0d04d-b5f5-462d-83ea-b7e3cce74399" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanEquitySecuritiesNonUsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_eb08ef9b-17db-4bd6-ba5f-9caae72dc76e" xlink:to="loc_us-gaap_DefinedBenefitPlanEquitySecuritiesNonUsMember_97a0d04d-b5f5-462d-83ea-b7e3cce74399" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_DefinedBenefitPlanDebtSecuritiesAndOtherNonUSMember_c78fec81-8e11-450b-9a3f-5bde87a21f3d" xlink:href="wab-20201231.xsd#wab_DefinedBenefitPlanDebtSecuritiesAndOtherNonUSMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_eb08ef9b-17db-4bd6-ba5f-9caae72dc76e" xlink:to="loc_wab_DefinedBenefitPlanDebtSecuritiesAndOtherNonUSMember_c78fec81-8e11-450b-9a3f-5bde87a21f3d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_InsuranceContractsMember_b9ca4487-cbcb-4909-86e0-e3b5546b7a05" xlink:href="wab-20201231.xsd#wab_InsuranceContractsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_eb08ef9b-17db-4bd6-ba5f-9caae72dc76e" xlink:to="loc_wab_InsuranceContractsMember_b9ca4487-cbcb-4909-86e0-e3b5546b7a05" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_DefinedBenefitPlanCashAndCashEquivalentsNonUSMember_df40676e-8ce8-47fc-bdf7-a3872278e982" xlink:href="wab-20201231.xsd#wab_DefinedBenefitPlanCashAndCashEquivalentsNonUSMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_eb08ef9b-17db-4bd6-ba5f-9caae72dc76e" xlink:to="loc_wab_DefinedBenefitPlanCashAndCashEquivalentsNonUSMember_df40676e-8ce8-47fc-bdf7-a3872278e982" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_ff6a1689-c454-49f2-9e05-6ec965437225" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_c48ad727-57aa-406e-a0bc-61d9115d9498" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_ff6a1689-c454-49f2-9e05-6ec965437225" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_ff6a1689-c454-49f2-9e05-6ec965437225_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_ff6a1689-c454-49f2-9e05-6ec965437225" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_ff6a1689-c454-49f2-9e05-6ec965437225_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_2de27362-8328-42f0-ba1d-fd356dcfb25b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_ff6a1689-c454-49f2-9e05-6ec965437225" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_2de27362-8328-42f0-ba1d-fd356dcfb25b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasuredAtNetAssetValuePerShareMember_0416d98f-f547-4469-8642-c7c5f4b2f766" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueMeasuredAtNetAssetValuePerShareMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_2de27362-8328-42f0-ba1d-fd356dcfb25b" xlink:to="loc_us-gaap_FairValueMeasuredAtNetAssetValuePerShareMember_0416d98f-f547-4469-8642-c7c5f4b2f766" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_12b5d0d2-62fb-4c17-a96a-2d0c7f52f3cb" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueInputsLevel1Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_2de27362-8328-42f0-ba1d-fd356dcfb25b" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_12b5d0d2-62fb-4c17-a96a-2d0c7f52f3cb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_e016523b-5b2d-4704-b457-8c3e04970a0a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_2de27362-8328-42f0-ba1d-fd356dcfb25b" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_e016523b-5b2d-4704-b457-8c3e04970a0a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_01bb90ec-2615-466e-a621-ccaeba147e02" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_2de27362-8328-42f0-ba1d-fd356dcfb25b" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_01bb90ec-2615-466e-a621-ccaeba147e02" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/EMPLOYEEBENEFITPLANSScheduleofReconciliationofLevel3AssetsDetails" xlink:type="simple" xlink:href="wab-20201231.xsd#EMPLOYEEBENEFITPLANSScheduleofReconciliationofLevel3AssetsDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/EMPLOYEEBENEFITPLANSScheduleofReconciliationofLevel3AssetsDetails" xlink:type="extended" id="i907082b298bc4f7c967c5704f680c13a_EMPLOYEEBENEFITPLANSScheduleofReconciliationofLevel3AssetsDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_49ade64c-9832-4e0f-a180-2745037c4aaf" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsLevel3ReconciliationRollForward_f96413ae-7084-4c59-b63b-1d7df2df052f" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsLevel3ReconciliationRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_49ade64c-9832-4e0f-a180-2745037c4aaf" xlink:to="loc_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsLevel3ReconciliationRollForward_f96413ae-7084-4c59-b63b-1d7df2df052f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_4c8524eb-4727-4209-b1ee-831948d1111a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanFairValueOfPlanAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsLevel3ReconciliationRollForward_f96413ae-7084-4c59-b63b-1d7df2df052f" xlink:to="loc_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_4c8524eb-4727-4209-b1ee-831948d1111a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanPurchasesSalesAndSettlements_113c9b62-62d7-4266-8a39-26befe45c6db" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanPurchasesSalesAndSettlements"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsLevel3ReconciliationRollForward_f96413ae-7084-4c59-b63b-1d7df2df052f" xlink:to="loc_us-gaap_DefinedBenefitPlanPurchasesSalesAndSettlements_113c9b62-62d7-4266-8a39-26befe45c6db" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanActualReturnOnPlanAssets_44c03072-3056-4e10-ba8c-9f985575c65b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanActualReturnOnPlanAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsLevel3ReconciliationRollForward_f96413ae-7084-4c59-b63b-1d7df2df052f" xlink:to="loc_us-gaap_DefinedBenefitPlanActualReturnOnPlanAssets_44c03072-3056-4e10-ba8c-9f985575c65b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanTransfersBetweenMeasurementLevels_0560513a-c1ee-4e24-a886-7e3d747961ac" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanTransfersBetweenMeasurementLevels"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsLevel3ReconciliationRollForward_f96413ae-7084-4c59-b63b-1d7df2df052f" xlink:to="loc_us-gaap_DefinedBenefitPlanTransfersBetweenMeasurementLevels_0560513a-c1ee-4e24-a886-7e3d747961ac" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_DefinedBenefitPlanPlanAssetsLevel3ReconciliationIncreaseDecreaseForeignCurrencyGainLoss_1a6d8ac4-e85f-4c95-8d6a-d31a6ded9eea" xlink:href="wab-20201231.xsd#wab_DefinedBenefitPlanPlanAssetsLevel3ReconciliationIncreaseDecreaseForeignCurrencyGainLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsLevel3ReconciliationRollForward_f96413ae-7084-4c59-b63b-1d7df2df052f" xlink:to="loc_wab_DefinedBenefitPlanPlanAssetsLevel3ReconciliationIncreaseDecreaseForeignCurrencyGainLoss_1a6d8ac4-e85f-4c95-8d6a-d31a6ded9eea" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_7db5509a-5b0c-434c-bd41-599712482548" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanFairValueOfPlanAssets"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_296a7b19-2563-4977-ac49-3bf5f9cb7615" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_49ade64c-9832-4e0f-a180-2745037c4aaf" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_296a7b19-2563-4977-ac49-3bf5f9cb7615" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_ad176e28-84b4-43b0-b326-11d823f44a14" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_296a7b19-2563-4977-ac49-3bf5f9cb7615" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_ad176e28-84b4-43b0-b326-11d823f44a14" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_ad176e28-84b4-43b0-b326-11d823f44a14_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_ad176e28-84b4-43b0-b326-11d823f44a14" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_ad176e28-84b4-43b0-b326-11d823f44a14_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_bbcce374-bd96-4d5a-a9c7-7b5dfb8ddf38" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_ad176e28-84b4-43b0-b326-11d823f44a14" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_bbcce374-bd96-4d5a-a9c7-7b5dfb8ddf38" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionPlansDefinedBenefitMember_577d8e3a-4f17-4bc4-85e7-1cda2f2019f0" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PensionPlansDefinedBenefitMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_bbcce374-bd96-4d5a-a9c7-7b5dfb8ddf38" xlink:to="loc_us-gaap_PensionPlansDefinedBenefitMember_577d8e3a-4f17-4bc4-85e7-1cda2f2019f0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_0657d0a4-d17f-4790-9955-787aef94cb5f" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_296a7b19-2563-4977-ac49-3bf5f9cb7615" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_0657d0a4-d17f-4790-9955-787aef94cb5f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_0657d0a4-d17f-4790-9955-787aef94cb5f_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_0657d0a4-d17f-4790-9955-787aef94cb5f" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_0657d0a4-d17f-4790-9955-787aef94cb5f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_0083184b-a5b8-4552-addb-229ade19638b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_0657d0a4-d17f-4790-9955-787aef94cb5f" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_0083184b-a5b8-4552-addb-229ade19638b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_fd24bdf5-eb60-4b93-955a-55892d8d17b0" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_0083184b-a5b8-4552-addb-229ade19638b" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_fd24bdf5-eb60-4b93-955a-55892d8d17b0" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/EMPLOYEEBENEFITPLANSBenefitPaymentsExpectedtobePaidtoPlanParticipantsDetails" xlink:type="simple" xlink:href="wab-20201231.xsd#EMPLOYEEBENEFITPLANSBenefitPaymentsExpectedtobePaidtoPlanParticipantsDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/EMPLOYEEBENEFITPLANSBenefitPaymentsExpectedtobePaidtoPlanParticipantsDetails" xlink:type="extended" id="i90bd852c80f84bb6906b995e515ce2d1_EMPLOYEEBENEFITPLANSBenefitPaymentsExpectedtobePaidtoPlanParticipantsDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_088da2c7-a029-4798-b2b4-ed5728d47cc3" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths_0090d705-a6d1-4704-8853-43116be54123" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_088da2c7-a029-4798-b2b4-ed5728d47cc3" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths_0090d705-a6d1-4704-8853-43116be54123" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo_947e036d-dc7c-4d7a-b09a-2806c7715292" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_088da2c7-a029-4798-b2b4-ed5728d47cc3" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo_947e036d-dc7c-4d7a-b09a-2806c7715292" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree_baea3e9b-4d02-4a84-9717-96db7021cc4f" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_088da2c7-a029-4798-b2b4-ed5728d47cc3" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree_baea3e9b-4d02-4a84-9717-96db7021cc4f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour_567c3f18-fdce-48a1-81e0-5a2af88e0956" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_088da2c7-a029-4798-b2b4-ed5728d47cc3" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour_567c3f18-fdce-48a1-81e0-5a2af88e0956" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive_d7209079-caf1-4e02-9906-f1d9cde7db66" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_088da2c7-a029-4798-b2b4-ed5728d47cc3" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive_d7209079-caf1-4e02-9906-f1d9cde7db66" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter_9d7cddbd-5bcb-4ea5-a0a9-ff1202cce4d1" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_088da2c7-a029-4798-b2b4-ed5728d47cc3" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter_9d7cddbd-5bcb-4ea5-a0a9-ff1202cce4d1" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_ae8f2cd6-c47d-4d94-afb4-4aa9dc87cb6a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_088da2c7-a029-4798-b2b4-ed5728d47cc3" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_ae8f2cd6-c47d-4d94-afb4-4aa9dc87cb6a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationAxis_631ce171-7264-445f-af72-731237a0791c" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanSponsorLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_ae8f2cd6-c47d-4d94-afb4-4aa9dc87cb6a" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationAxis_631ce171-7264-445f-af72-731237a0791c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_631ce171-7264-445f-af72-731237a0791c_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_631ce171-7264-445f-af72-731237a0791c" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_631ce171-7264-445f-af72-731237a0791c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_f50a374d-f4b8-4609-9a42-522f2f5df8f0" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_631ce171-7264-445f-af72-731237a0791c" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_f50a374d-f4b8-4609-9a42-522f2f5df8f0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DomesticPlanMember_cedd487e-60df-4acf-bdf3-0c2abd649f64" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DomesticPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_f50a374d-f4b8-4609-9a42-522f2f5df8f0" xlink:to="loc_us-gaap_DomesticPlanMember_cedd487e-60df-4acf-bdf3-0c2abd649f64" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_US_cd88c99f-5bbc-4fde-81ff-8d4ea5f871f6" xlink:href="https://xbrl.sec.gov/country/2020/country-2020-01-31.xsd#country_US"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DomesticPlanMember_cedd487e-60df-4acf-bdf3-0c2abd649f64" xlink:to="loc_country_US_cd88c99f-5bbc-4fde-81ff-8d4ea5f871f6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignPlanMember_1ffde00d-1d5f-47ec-a48b-0a9821bdaf31" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ForeignPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_f50a374d-f4b8-4609-9a42-522f2f5df8f0" xlink:to="loc_us-gaap_ForeignPlanMember_1ffde00d-1d5f-47ec-a48b-0a9821bdaf31" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_e3372be0-f2da-4cd7-bcd7-4a2686500717" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_ae8f2cd6-c47d-4d94-afb4-4aa9dc87cb6a" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_e3372be0-f2da-4cd7-bcd7-4a2686500717" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_e3372be0-f2da-4cd7-bcd7-4a2686500717_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_e3372be0-f2da-4cd7-bcd7-4a2686500717" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_e3372be0-f2da-4cd7-bcd7-4a2686500717_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_3b028cd8-9774-45bc-8679-be4a363edf1c" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_e3372be0-f2da-4cd7-bcd7-4a2686500717" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_3b028cd8-9774-45bc-8679-be4a363edf1c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionPlansDefinedBenefitMember_49f72e44-cfb3-443e-800b-2028e1bfcbdf" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PensionPlansDefinedBenefitMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_3b028cd8-9774-45bc-8679-be4a363edf1c" xlink:to="loc_us-gaap_PensionPlansDefinedBenefitMember_49f72e44-cfb3-443e-800b-2028e1bfcbdf" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/EMPLOYEEBENEFITPLANSCostsRecognizedUnderDefinedContributionPlansandMultiemployerPensionPlansDetails" xlink:type="simple" xlink:href="wab-20201231.xsd#EMPLOYEEBENEFITPLANSCostsRecognizedUnderDefinedContributionPlansandMultiemployerPensionPlansDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/EMPLOYEEBENEFITPLANSCostsRecognizedUnderDefinedContributionPlansandMultiemployerPensionPlansDetails" xlink:type="extended" id="i6af2153afc8b4d84b269d65eab646f53_EMPLOYEEBENEFITPLANSCostsRecognizedUnderDefinedContributionPlansandMultiemployerPensionPlansDetails"/>
  <link:roleRef roleURI="http://wabtec.com/role/INCOMETAXES" xlink:type="simple" xlink:href="wab-20201231.xsd#INCOMETAXES"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/INCOMETAXES" xlink:type="extended" id="ifc47a6f877574730b197ebcd0bd31301_INCOMETAXES"/>
  <link:roleRef roleURI="http://wabtec.com/role/INCOMETAXESTables" xlink:type="simple" xlink:href="wab-20201231.xsd#INCOMETAXESTables"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/INCOMETAXESTables" xlink:type="extended" id="ic01e174370344629835107da1a9dd365_INCOMETAXESTables"/>
  <link:roleRef roleURI="http://wabtec.com/role/INCOMETAXESNarrativeDetails" xlink:type="simple" xlink:href="wab-20201231.xsd#INCOMETAXESNarrativeDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/INCOMETAXESNarrativeDetails" xlink:type="extended" id="ic8d8258fee8c4fc2a4799f29474e3d95_INCOMETAXESNarrativeDetails"/>
  <link:roleRef roleURI="http://wabtec.com/role/INCOMETAXESComponentsofIncomefromOperationsbeforeProvisionforIncomeTaxesDetails" xlink:type="simple" xlink:href="wab-20201231.xsd#INCOMETAXESComponentsofIncomefromOperationsbeforeProvisionforIncomeTaxesDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/INCOMETAXESComponentsofIncomefromOperationsbeforeProvisionforIncomeTaxesDetails" xlink:type="extended" id="i69be0ca611314746a43b867ded6f2c2c_INCOMETAXESComponentsofIncomefromOperationsbeforeProvisionforIncomeTaxesDetails"/>
  <link:roleRef roleURI="http://wabtec.com/role/INCOMETAXESConsolidatedProvisionforIncomeTaxesDetails" xlink:type="simple" xlink:href="wab-20201231.xsd#INCOMETAXESConsolidatedProvisionforIncomeTaxesDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/INCOMETAXESConsolidatedProvisionforIncomeTaxesDetails" xlink:type="extended" id="i4c7a1ad869b2412e9b48ffaba2ccc16d_INCOMETAXESConsolidatedProvisionforIncomeTaxesDetails"/>
  <link:roleRef roleURI="http://wabtec.com/role/INCOMETAXESReconciliationofIncomeTaxRateDetails" xlink:type="simple" xlink:href="wab-20201231.xsd#INCOMETAXESReconciliationofIncomeTaxRateDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/INCOMETAXESReconciliationofIncomeTaxRateDetails" xlink:type="extended" id="ief93d870f5ae4fbf948953fddba17703_INCOMETAXESReconciliationofIncomeTaxRateDetails"/>
  <link:roleRef roleURI="http://wabtec.com/role/INCOMETAXESComponentsofDeferredTaxAssetsandLiabilitiesDetails" xlink:type="simple" xlink:href="wab-20201231.xsd#INCOMETAXESComponentsofDeferredTaxAssetsandLiabilitiesDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/INCOMETAXESComponentsofDeferredTaxAssetsandLiabilitiesDetails" xlink:type="extended" id="i44a155aa0b2b4fdc8aed34b000998b0f_INCOMETAXESComponentsofDeferredTaxAssetsandLiabilitiesDetails"/>
  <link:roleRef roleURI="http://wabtec.com/role/INCOMETAXESLiabilityforIncomeTaxesAssociatedwithUncertainTaxPositionsDetails" xlink:type="simple" xlink:href="wab-20201231.xsd#INCOMETAXESLiabilityforIncomeTaxesAssociatedwithUncertainTaxPositionsDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/INCOMETAXESLiabilityforIncomeTaxesAssociatedwithUncertainTaxPositionsDetails" xlink:type="extended" id="i1a4a4dfb0b2a4f3b8c4d731e20fc3e2e_INCOMETAXESLiabilityforIncomeTaxesAssociatedwithUncertainTaxPositionsDetails"/>
  <link:roleRef roleURI="http://wabtec.com/role/EARNINGSPERSHARE" xlink:type="simple" xlink:href="wab-20201231.xsd#EARNINGSPERSHARE"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/EARNINGSPERSHARE" xlink:type="extended" id="i55ecddbfeabd4826b21af05d9aa42744_EARNINGSPERSHARE"/>
  <link:roleRef roleURI="http://wabtec.com/role/EARNINGSPERSHARETables" xlink:type="simple" xlink:href="wab-20201231.xsd#EARNINGSPERSHARETables"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/EARNINGSPERSHARETables" xlink:type="extended" id="i5e5c18a2a7a24c228239c08b5e13c230_EARNINGSPERSHARETables"/>
  <link:roleRef roleURI="http://wabtec.com/role/EARNINGSPERSHAREComputationofEarningsPerShareDetails" xlink:type="simple" xlink:href="wab-20201231.xsd#EARNINGSPERSHAREComputationofEarningsPerShareDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/EARNINGSPERSHAREComputationofEarningsPerShareDetails" xlink:type="extended" id="ifdc523c91cc74e1b92cd83e62629c3fb_EARNINGSPERSHAREComputationofEarningsPerShareDetails"/>
  <link:roleRef roleURI="http://wabtec.com/role/EARNINGSPERSHARENarrativeDetails" xlink:type="simple" xlink:href="wab-20201231.xsd#EARNINGSPERSHARENarrativeDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/EARNINGSPERSHARENarrativeDetails" xlink:type="extended" id="icf276dd81a47419a897054d69cd633a2_EARNINGSPERSHARENarrativeDetails"/>
  <link:roleRef roleURI="http://wabtec.com/role/STOCKBASEDCOMPENSATIONPLANS" xlink:type="simple" xlink:href="wab-20201231.xsd#STOCKBASEDCOMPENSATIONPLANS"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/STOCKBASEDCOMPENSATIONPLANS" xlink:type="extended" id="ifa7cdb4db816457297cc15415b49dfb3_STOCKBASEDCOMPENSATIONPLANS"/>
  <link:roleRef roleURI="http://wabtec.com/role/STOCKBASEDCOMPENSATIONPLANSTables" xlink:type="simple" xlink:href="wab-20201231.xsd#STOCKBASEDCOMPENSATIONPLANSTables"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/STOCKBASEDCOMPENSATIONPLANSTables" xlink:type="extended" id="i7e0c9af161a3452d845b46f5c6214b5e_STOCKBASEDCOMPENSATIONPLANSTables"/>
  <link:roleRef roleURI="http://wabtec.com/role/STOCKBASEDCOMPENSATIONPLANSNarrativeDetails" xlink:type="simple" xlink:href="wab-20201231.xsd#STOCKBASEDCOMPENSATIONPLANSNarrativeDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/STOCKBASEDCOMPENSATIONPLANSNarrativeDetails" xlink:type="extended" id="i34db665f09b842adbf3b2cc4568eecc2_STOCKBASEDCOMPENSATIONPLANSNarrativeDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_ed57fca3-6b33-41fa-b5c6-49c8568e8468" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_d722ff5d-e7f6-4b8a-aec0-972cff1a3ec9" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_ed57fca3-6b33-41fa-b5c6-49c8568e8468" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_d722ff5d-e7f6-4b8a-aec0-972cff1a3ec9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_6dfe3a6d-13c8-4fd3-b54d-4807556bb4ae" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_ed57fca3-6b33-41fa-b5c6-49c8568e8468" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_6dfe3a6d-13c8-4fd3-b54d-4807556bb4ae" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_0c491794-f1af-443b-96b9-e4860284ce11" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_ed57fca3-6b33-41fa-b5c6-49c8568e8468" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_0c491794-f1af-443b-96b9-e4860284ce11" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod_135aea80-08db-47cf-a462-160f9e930596" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_ed57fca3-6b33-41fa-b5c6-49c8568e8468" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod_135aea80-08db-47cf-a462-160f9e930596" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod_ba0e29c2-6811-48c3-b97d-81fbb1e0b3d4" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_ed57fca3-6b33-41fa-b5c6-49c8568e8468" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod_ba0e29c2-6811-48c3-b97d-81fbb1e0b3d4" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_7eb16b7f-be3a-4767-b9cb-be12a4139ac6" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_ed57fca3-6b33-41fa-b5c6-49c8568e8468" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_7eb16b7f-be3a-4767-b9cb-be12a4139ac6" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromExerciseOfStockOptions_aae48dc0-1d6d-4f54-9076-f7804a542b6e" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromExerciseOfStockOptions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_ed57fca3-6b33-41fa-b5c6-49c8568e8468" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromExerciseOfStockOptions_aae48dc0-1d6d-4f54-9076-f7804a542b6e" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_9a0b42cf-c8d3-4aa9-b3fa-15a3d024e1bc" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_ed57fca3-6b33-41fa-b5c6-49c8568e8468" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_9a0b42cf-c8d3-4aa9-b3fa-15a3d024e1bc" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_c6e64e50-6126-49ae-8b98-59ca75791d08" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_ed57fca3-6b33-41fa-b5c6-49c8568e8468" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_c6e64e50-6126-49ae-8b98-59ca75791d08" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRateExpectedLife_2e1717d2-ef79-484c-9012-7b51f58c34b9" xlink:href="wab-20201231.xsd#wab_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRateExpectedLife"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_ed57fca3-6b33-41fa-b5c6-49c8568e8468" xlink:to="loc_wab_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRateExpectedLife_2e1717d2-ef79-484c-9012-7b51f58c34b9" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage_587b107b-882d-4040-acfa-f0d05c76565c" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_ed57fca3-6b33-41fa-b5c6-49c8568e8468" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage_587b107b-882d-4040-acfa-f0d05c76565c" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_f1a1e4f8-0e82-456b-abb2-015f99b36277" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_ed57fca3-6b33-41fa-b5c6-49c8568e8468" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_f1a1e4f8-0e82-456b-abb2-015f99b36277" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameAxis_8ddd806a-b5a7-4ee2-a3c8-1c22769f8d2d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PlanNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_f1a1e4f8-0e82-456b-abb2-015f99b36277" xlink:to="loc_us-gaap_PlanNameAxis_8ddd806a-b5a7-4ee2-a3c8-1c22769f8d2d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_8ddd806a-b5a7-4ee2-a3c8-1c22769f8d2d_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PlanNameAxis_8ddd806a-b5a7-4ee2-a3c8-1c22769f8d2d" xlink:to="loc_us-gaap_PlanNameDomain_8ddd806a-b5a7-4ee2-a3c8-1c22769f8d2d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_b84aff44-f10c-499a-a4aa-c7f69005cbb4" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PlanNameAxis_8ddd806a-b5a7-4ee2-a3c8-1c22769f8d2d" xlink:to="loc_us-gaap_PlanNameDomain_b84aff44-f10c-499a-a4aa-c7f69005cbb4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_PlanTwoThousandElevenMember_4ef11ea5-07c2-411f-a524-afc0191465c0" xlink:href="wab-20201231.xsd#wab_PlanTwoThousandElevenMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_b84aff44-f10c-499a-a4aa-c7f69005cbb4" xlink:to="loc_wab_PlanTwoThousandElevenMember_4ef11ea5-07c2-411f-a524-afc0191465c0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_DirectorsPlanMember_bd69f422-f629-431e-aec3-d36a301ba279" xlink:href="wab-20201231.xsd#wab_DirectorsPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_b84aff44-f10c-499a-a4aa-c7f69005cbb4" xlink:to="loc_wab_DirectorsPlanMember_bd69f422-f629-431e-aec3-d36a301ba279" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_PlanTwoThousandMember_efb9b577-92c2-4f2b-8c9b-a00d9ed868fc" xlink:href="wab-20201231.xsd#wab_PlanTwoThousandMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_b84aff44-f10c-499a-a4aa-c7f69005cbb4" xlink:to="loc_wab_PlanTwoThousandMember_efb9b577-92c2-4f2b-8c9b-a00d9ed868fc" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_b47d52d7-e82c-4e1a-b1d4-06c10f7e9476" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_f1a1e4f8-0e82-456b-abb2-015f99b36277" xlink:to="loc_us-gaap_AwardTypeAxis_b47d52d7-e82c-4e1a-b1d4-06c10f7e9476" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_b47d52d7-e82c-4e1a-b1d4-06c10f7e9476_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_b47d52d7-e82c-4e1a-b1d4-06c10f7e9476" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_b47d52d7-e82c-4e1a-b1d4-06c10f7e9476_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_7da64efd-b67f-4e06-b914-36e8036aa6a5" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_b47d52d7-e82c-4e1a-b1d4-06c10f7e9476" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_7da64efd-b67f-4e06-b914-36e8036aa6a5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockOptionMember_73696def-992b-491e-abc4-dc53e0e507fc" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EmployeeStockOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_7da64efd-b67f-4e06-b914-36e8036aa6a5" xlink:to="loc_us-gaap_EmployeeStockOptionMember_73696def-992b-491e-abc4-dc53e0e507fc" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockMember_919c5d2c-4a48-4df8-9326-1e720c6e756b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RestrictedStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_7da64efd-b67f-4e06-b914-36e8036aa6a5" xlink:to="loc_us-gaap_RestrictedStockMember_919c5d2c-4a48-4df8-9326-1e720c6e756b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_NonVestedRestrictedStockMember_96c40503-bb8d-4c66-a7ac-58a2c70dbffb" xlink:href="wab-20201231.xsd#wab_NonVestedRestrictedStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_7da64efd-b67f-4e06-b914-36e8036aa6a5" xlink:to="loc_wab_NonVestedRestrictedStockMember_96c40503-bb8d-4c66-a7ac-58a2c70dbffb" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_35508d43-6348-43a5-a213-f8a17c86e368" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RestrictedStockUnitsRSUMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_7da64efd-b67f-4e06-b914-36e8036aa6a5" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_35508d43-6348-43a5-a213-f8a17c86e368" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PerformanceSharesMember_aad2aa14-dd6e-493e-9f8d-b6f35c493a6b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PerformanceSharesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_7da64efd-b67f-4e06-b914-36e8036aa6a5" xlink:to="loc_us-gaap_PerformanceSharesMember_aad2aa14-dd6e-493e-9f8d-b6f35c493a6b" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_0d6c536b-1a67-440e-b1b0-04c4fbfe7065" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_f1a1e4f8-0e82-456b-abb2-015f99b36277" xlink:to="loc_srt_RangeAxis_0d6c536b-1a67-440e-b1b0-04c4fbfe7065" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_0d6c536b-1a67-440e-b1b0-04c4fbfe7065_default" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_0d6c536b-1a67-440e-b1b0-04c4fbfe7065" xlink:to="loc_srt_RangeMember_0d6c536b-1a67-440e-b1b0-04c4fbfe7065_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_7af46acb-c63d-45db-afba-90b3eabdb560" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_0d6c536b-1a67-440e-b1b0-04c4fbfe7065" xlink:to="loc_srt_RangeMember_7af46acb-c63d-45db-afba-90b3eabdb560" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_43f608bd-ffc0-4ba0-b33b-2ec3c094dde9" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_7af46acb-c63d-45db-afba-90b3eabdb560" xlink:to="loc_srt_MinimumMember_43f608bd-ffc0-4ba0-b33b-2ec3c094dde9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_e4ba8b89-4dfd-4081-aa34-91b49aa916d0" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_7af46acb-c63d-45db-afba-90b3eabdb560" xlink:to="loc_srt_MaximumMember_e4ba8b89-4dfd-4081-aa34-91b49aa916d0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementScenarioAxis_928d4c56-507e-4f71-8c64-afd62a09e0ae" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_StatementScenarioAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_f1a1e4f8-0e82-456b-abb2-015f99b36277" xlink:to="loc_srt_StatementScenarioAxis_928d4c56-507e-4f71-8c64-afd62a09e0ae" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScenarioUnspecifiedDomain_928d4c56-507e-4f71-8c64-afd62a09e0ae_default" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ScenarioUnspecifiedDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementScenarioAxis_928d4c56-507e-4f71-8c64-afd62a09e0ae" xlink:to="loc_srt_ScenarioUnspecifiedDomain_928d4c56-507e-4f71-8c64-afd62a09e0ae_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScenarioUnspecifiedDomain_24c6b579-3f2e-47bf-b830-31c223703f93" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ScenarioUnspecifiedDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementScenarioAxis_928d4c56-507e-4f71-8c64-afd62a09e0ae" xlink:to="loc_srt_ScenarioUnspecifiedDomain_24c6b579-3f2e-47bf-b830-31c223703f93" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScenarioForecastMember_3512ad79-a2f5-4fb6-8584-f5cd191ce82f" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ScenarioForecastMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ScenarioUnspecifiedDomain_24c6b579-3f2e-47bf-b830-31c223703f93" xlink:to="loc_srt_ScenarioForecastMember_3512ad79-a2f5-4fb6-8584-f5cd191ce82f" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/STOCKBASEDCOMPENSATIONPLANSStockOptionActivityDetails" xlink:type="simple" xlink:href="wab-20201231.xsd#STOCKBASEDCOMPENSATIONPLANSStockOptionActivityDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/STOCKBASEDCOMPENSATIONPLANSStockOptionActivityDetails" xlink:type="extended" id="ic5037f38f0094078ab66631bb27a2dac_STOCKBASEDCOMPENSATIONPLANSStockOptionActivityDetails"/>
  <link:roleRef roleURI="http://wabtec.com/role/STOCKBASEDCOMPENSATIONPLANSStockOptionsOutstandingDetails" xlink:type="simple" xlink:href="wab-20201231.xsd#STOCKBASEDCOMPENSATIONPLANSStockOptionsOutstandingDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/STOCKBASEDCOMPENSATIONPLANSStockOptionsOutstandingDetails" xlink:type="extended" id="ie56a79999cb24153a2efe8b97fd44466_STOCKBASEDCOMPENSATIONPLANSStockOptionsOutstandingDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems_0ec54b63-e21f-435c-9e61-2ad600039ac5" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLowerRangeLimit_6e144e4c-ecd7-4747-868a-711776278d99" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLowerRangeLimit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems_0ec54b63-e21f-435c-9e61-2ad600039ac5" xlink:to="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLowerRangeLimit_6e144e4c-ecd7-4747-868a-711776278d99" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit_9ccd93b8-7b70-4d74-8079-e548c733a17c" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems_0ec54b63-e21f-435c-9e61-2ad600039ac5" xlink:to="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit_9ccd93b8-7b70-4d74-8079-e548c733a17c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfOutstandingOptions_4cea04ac-4df9-4a8a-8778-6f4aa8917de3" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfOutstandingOptions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems_0ec54b63-e21f-435c-9e61-2ad600039ac5" xlink:to="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfOutstandingOptions_4cea04ac-4df9-4a8a-8778-6f4aa8917de3" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeOutstandingOptionsWeightedAverageExercisePriceBeginningBalance1_43afb7b9-bfa9-4dbe-a921-eb765c3a8bde" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeOutstandingOptionsWeightedAverageExercisePriceBeginningBalance1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems_0ec54b63-e21f-435c-9e61-2ad600039ac5" xlink:to="loc_us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeOutstandingOptionsWeightedAverageExercisePriceBeginningBalance1_43afb7b9-bfa9-4dbe-a921-eb765c3a8bde" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeOutstandingOptionsWeightedAverageRemainingContractualTerm2_68821c58-629f-4fa6-bf73-f3923a862649" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeOutstandingOptionsWeightedAverageRemainingContractualTerm2"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems_0ec54b63-e21f-435c-9e61-2ad600039ac5" xlink:to="loc_us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeOutstandingOptionsWeightedAverageRemainingContractualTerm2_68821c58-629f-4fa6-bf73-f3923a862649" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfExercisableOptions_bab814a2-ed31-4b8f-a13d-579813cee622" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfExercisableOptions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems_0ec54b63-e21f-435c-9e61-2ad600039ac5" xlink:to="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfExercisableOptions_bab814a2-ed31-4b8f-a13d-579813cee622" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeExercisableOptionsWeightedAverageExercisePrice1_44c34057-a39b-4edd-923f-218b21387819" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeExercisableOptionsWeightedAverageExercisePrice1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems_0ec54b63-e21f-435c-9e61-2ad600039ac5" xlink:to="loc_us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeExercisableOptionsWeightedAverageExercisePrice1_44c34057-a39b-4edd-923f-218b21387819" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeTable_5111a861-9f2a-4962-9599-1f80741f6343" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems_0ec54b63-e21f-435c-9e61-2ad600039ac5" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeTable_5111a861-9f2a-4962-9599-1f80741f6343" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis_8520ed9f-f14c-4caa-bd01-ce5d874235d7" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeTable_5111a861-9f2a-4962-9599-1f80741f6343" xlink:to="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis_8520ed9f-f14c-4caa-bd01-ce5d874235d7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain_8520ed9f-f14c-4caa-bd01-ce5d874235d7_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis_8520ed9f-f14c-4caa-bd01-ce5d874235d7" xlink:to="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain_8520ed9f-f14c-4caa-bd01-ce5d874235d7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain_4826da1d-2bb0-4652-a055-d219364f709b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis_8520ed9f-f14c-4caa-bd01-ce5d874235d7" xlink:to="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain_4826da1d-2bb0-4652-a055-d219364f709b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_ExercisePriceRangeOneMember_73c3f946-6f44-477e-903b-1f308828c5ef" xlink:href="wab-20201231.xsd#wab_ExercisePriceRangeOneMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain_4826da1d-2bb0-4652-a055-d219364f709b" xlink:to="loc_wab_ExercisePriceRangeOneMember_73c3f946-6f44-477e-903b-1f308828c5ef" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_ExercisePriceRangeTwoMember_1fb66f0c-0cbc-4320-adab-169e4d8444e4" xlink:href="wab-20201231.xsd#wab_ExercisePriceRangeTwoMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain_4826da1d-2bb0-4652-a055-d219364f709b" xlink:to="loc_wab_ExercisePriceRangeTwoMember_1fb66f0c-0cbc-4320-adab-169e4d8444e4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_ExercisePriceRangeThreeMember_7793ce3e-2cbf-46c7-98cc-a72885fc58eb" xlink:href="wab-20201231.xsd#wab_ExercisePriceRangeThreeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain_4826da1d-2bb0-4652-a055-d219364f709b" xlink:to="loc_wab_ExercisePriceRangeThreeMember_7793ce3e-2cbf-46c7-98cc-a72885fc58eb" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_ExercisePriceRangeFourMember_6b27ad7c-3101-4832-bf16-239b380e8f52" xlink:href="wab-20201231.xsd#wab_ExercisePriceRangeFourMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain_4826da1d-2bb0-4652-a055-d219364f709b" xlink:to="loc_wab_ExercisePriceRangeFourMember_6b27ad7c-3101-4832-bf16-239b380e8f52" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_ExercisePriceRangeFiveMember_d539e2bb-52c9-417c-8d8c-914ee9408d27" xlink:href="wab-20201231.xsd#wab_ExercisePriceRangeFiveMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain_4826da1d-2bb0-4652-a055-d219364f709b" xlink:to="loc_wab_ExercisePriceRangeFiveMember_d539e2bb-52c9-417c-8d8c-914ee9408d27" xlink:type="arc" order="4"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/STOCKBASEDCOMPENSATIONPLANSScheduleofShareBasedFairValueofEachOptionGrantWeightedAverageAssumptionsDetails" xlink:type="simple" xlink:href="wab-20201231.xsd#STOCKBASEDCOMPENSATIONPLANSScheduleofShareBasedFairValueofEachOptionGrantWeightedAverageAssumptionsDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/STOCKBASEDCOMPENSATIONPLANSScheduleofShareBasedFairValueofEachOptionGrantWeightedAverageAssumptionsDetails" xlink:type="extended" id="i61d9d9c4460546c18880142958947009_STOCKBASEDCOMPENSATIONPLANSScheduleofShareBasedFairValueofEachOptionGrantWeightedAverageAssumptionsDetails"/>
  <link:roleRef roleURI="http://wabtec.com/role/STOCKBASEDCOMPENSATIONPLANSRestrictedStockActivityandIncentiveStockAwardsActivityDetails" xlink:type="simple" xlink:href="wab-20201231.xsd#STOCKBASEDCOMPENSATIONPLANSRestrictedStockActivityandIncentiveStockAwardsActivityDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/STOCKBASEDCOMPENSATIONPLANSRestrictedStockActivityandIncentiveStockAwardsActivityDetails" xlink:type="extended" id="ib68582265e25441badeb1075ea10d548_STOCKBASEDCOMPENSATIONPLANSRestrictedStockActivityandIncentiveStockAwardsActivityDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_2699611a-245f-4340-b796-3a79546c6dee" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_2cb7fd2e-9935-4497-a86e-3d28277194d0" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_2699611a-245f-4340-b796-3a79546c6dee" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_2cb7fd2e-9935-4497-a86e-3d28277194d0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_e9d0c652-9305-4c67-8d8d-a1094d613cd9" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_2cb7fd2e-9935-4497-a86e-3d28277194d0" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_e9d0c652-9305-4c67-8d8d-a1094d613cd9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_a323a734-c8fb-4e25-9b4d-9faa2feaa926" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_2cb7fd2e-9935-4497-a86e-3d28277194d0" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_a323a734-c8fb-4e25-9b4d-9faa2feaa926" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_741801fc-e433-401f-a48c-92dfc8b87548" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_2cb7fd2e-9935-4497-a86e-3d28277194d0" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_741801fc-e433-401f-a48c-92dfc8b87548" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumberExpectedToVest_ed94a142-e5b9-45e9-9a37-1c9af3cf4646" xlink:href="wab-20201231.xsd#wab_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumberExpectedToVest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_2cb7fd2e-9935-4497-a86e-3d28277194d0" xlink:to="loc_wab_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumberExpectedToVest_ed94a142-e5b9-45e9-9a37-1c9af3cf4646" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_11c7d448-4e81-4532-8ef1-25a99c8cc594" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_2cb7fd2e-9935-4497-a86e-3d28277194d0" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_11c7d448-4e81-4532-8ef1-25a99c8cc594" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_2f45fa09-99d7-46a5-8c3d-8635873e08e7" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_d80dd906-577f-4185-b34a-74b0112f1c76" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_2699611a-245f-4340-b796-3a79546c6dee" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_d80dd906-577f-4185-b34a-74b0112f1c76" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_b2b4a635-a7a0-4644-ba42-0cda55023ec8" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_d80dd906-577f-4185-b34a-74b0112f1c76" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_b2b4a635-a7a0-4644-ba42-0cda55023ec8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_b05e0d20-c29c-4b57-aa3f-a359dcd4b7df" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_d80dd906-577f-4185-b34a-74b0112f1c76" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_b05e0d20-c29c-4b57-aa3f-a359dcd4b7df" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_e69bbb10-ae48-4b84-b896-6da68e9dd74d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_d80dd906-577f-4185-b34a-74b0112f1c76" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_e69bbb10-ae48-4b84-b896-6da68e9dd74d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNetPerformanceAdjustmentWeightedAverageNetPerformanceAdjustmentFairValue_1fb6e9a4-262d-4930-93f5-02f65e87232d" xlink:href="wab-20201231.xsd#wab_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNetPerformanceAdjustmentWeightedAverageNetPerformanceAdjustmentFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_d80dd906-577f-4185-b34a-74b0112f1c76" xlink:to="loc_wab_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNetPerformanceAdjustmentWeightedAverageNetPerformanceAdjustmentFairValue_1fb6e9a4-262d-4930-93f5-02f65e87232d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_6559c631-a4f2-4f94-9b24-baf2999ea7b9" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_d80dd906-577f-4185-b34a-74b0112f1c76" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_6559c631-a4f2-4f94-9b24-baf2999ea7b9" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_f3b5ccdd-8be3-4fb2-b61b-2ea8b9785e48" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_4cba00fd-8a78-4721-9a66-c7299310a72a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_2699611a-245f-4340-b796-3a79546c6dee" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_4cba00fd-8a78-4721-9a66-c7299310a72a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_30d196fc-8480-416e-a051-4d28abb27cfb" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_4cba00fd-8a78-4721-9a66-c7299310a72a" xlink:to="loc_us-gaap_AwardTypeAxis_30d196fc-8480-416e-a051-4d28abb27cfb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_30d196fc-8480-416e-a051-4d28abb27cfb_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_30d196fc-8480-416e-a051-4d28abb27cfb" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_30d196fc-8480-416e-a051-4d28abb27cfb_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_374c9334-8e03-4bc3-ac86-e5042c4ade93" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_30d196fc-8480-416e-a051-4d28abb27cfb" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_374c9334-8e03-4bc3-ac86-e5042c4ade93" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_RestrictedStockAndUnitsMember_e7fcf8b5-c7eb-40c6-9216-ae2ac6f9c081" xlink:href="wab-20201231.xsd#wab_RestrictedStockAndUnitsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_374c9334-8e03-4bc3-ac86-e5042c4ade93" xlink:to="loc_wab_RestrictedStockAndUnitsMember_e7fcf8b5-c7eb-40c6-9216-ae2ac6f9c081" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PerformanceSharesMember_ee297828-bd2d-4b5c-968b-5d3c75f44bb4" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PerformanceSharesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_374c9334-8e03-4bc3-ac86-e5042c4ade93" xlink:to="loc_us-gaap_PerformanceSharesMember_ee297828-bd2d-4b5c-968b-5d3c75f44bb4" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/OTHERCOMPREHENSIVELOSS" xlink:type="simple" xlink:href="wab-20201231.xsd#OTHERCOMPREHENSIVELOSS"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/OTHERCOMPREHENSIVELOSS" xlink:type="extended" id="i0da0502cd4f94deb9e07f63d96e13e6b_OTHERCOMPREHENSIVELOSS"/>
  <link:roleRef roleURI="http://wabtec.com/role/OTHERCOMPREHENSIVELOSSTables" xlink:type="simple" xlink:href="wab-20201231.xsd#OTHERCOMPREHENSIVELOSSTables"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/OTHERCOMPREHENSIVELOSSTables" xlink:type="extended" id="i5a103dd6f25843ed8a069b97a6ba3696_OTHERCOMPREHENSIVELOSSTables"/>
  <link:roleRef roleURI="http://wabtec.com/role/OTHERCOMPREHENSIVELOSSComponentsofAccumulatedOtherComprehensiveLossDetails" xlink:type="simple" xlink:href="wab-20201231.xsd#OTHERCOMPREHENSIVELOSSComponentsofAccumulatedOtherComprehensiveLossDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/OTHERCOMPREHENSIVELOSSComponentsofAccumulatedOtherComprehensiveLossDetails" xlink:type="extended" id="ida844e31c00049f7844c4dd6ffb19792_OTHERCOMPREHENSIVELOSSComponentsofAccumulatedOtherComprehensiveLossDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_2b91d80d-92a1-4a20-ac94-280930a73f2d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementOfFinancialPositionAbstract_f8608a5e-48cb-4d5f-9406-288f73820453" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementOfFinancialPositionAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_2b91d80d-92a1-4a20-ac94-280930a73f2d" xlink:to="loc_us-gaap_StatementOfFinancialPositionAbstract_f8608a5e-48cb-4d5f-9406-288f73820453" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_45c3aff2-83b7-465d-9903-73c0754891c5" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementOfFinancialPositionAbstract_f8608a5e-48cb-4d5f-9406-288f73820453" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_45c3aff2-83b7-465d-9903-73c0754891c5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AociIncludingPortionAttributableToNoncontrollingInterestTax_b8a3d40c-c487-433e-81bd-20ed8a478c17" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AociIncludingPortionAttributableToNoncontrollingInterestTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementOfFinancialPositionAbstract_f8608a5e-48cb-4d5f-9406-288f73820453" xlink:to="loc_us-gaap_AociIncludingPortionAttributableToNoncontrollingInterestTax_b8a3d40c-c487-433e-81bd-20ed8a478c17" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_fe3559c1-29ac-4645-8812-419d5e53512a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_2b91d80d-92a1-4a20-ac94-280930a73f2d" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_fe3559c1-29ac-4645-8812-419d5e53512a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_2547f152-df35-479c-9500-94d9637ef95f" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_fe3559c1-29ac-4645-8812-419d5e53512a" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_2547f152-df35-479c-9500-94d9637ef95f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_2547f152-df35-479c-9500-94d9637ef95f_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_2547f152-df35-479c-9500-94d9637ef95f" xlink:to="loc_us-gaap_EquityComponentDomain_2547f152-df35-479c-9500-94d9637ef95f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_6d8dcb15-aeef-4aff-a29c-64e8cae05b45" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_2547f152-df35-479c-9500-94d9637ef95f" xlink:to="loc_us-gaap_EquityComponentDomain_6d8dcb15-aeef-4aff-a29c-64e8cae05b45" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedTranslationAdjustmentMember_d8e66824-8d99-41b1-83c7-88fd6eafe790" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccumulatedTranslationAdjustmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_6d8dcb15-aeef-4aff-a29c-64e8cae05b45" xlink:to="loc_us-gaap_AccumulatedTranslationAdjustmentMember_d8e66824-8d99-41b1-83c7-88fd6eafe790" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember_6976232f-7e2d-4a2a-8353-05f48f1b50b0" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_6d8dcb15-aeef-4aff-a29c-64e8cae05b45" xlink:to="loc_us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember_6976232f-7e2d-4a2a-8353-05f48f1b50b0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember_9906e044-1d04-4160-9fbc-9c3533888c16" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_6d8dcb15-aeef-4aff-a29c-64e8cae05b45" xlink:to="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember_9906e044-1d04-4160-9fbc-9c3533888c16" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_3033ab8b-cfb4-4297-8a14-f1317a8398c7" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_6d8dcb15-aeef-4aff-a29c-64e8cae05b45" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_3033ab8b-cfb4-4297-8a14-f1317a8398c7" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/OTHERCOMPREHENSIVELOSSChangesinAccumulatedOtherComprehensiveLossbyComponentNetofTaxDetails" xlink:type="simple" xlink:href="wab-20201231.xsd#OTHERCOMPREHENSIVELOSSChangesinAccumulatedOtherComprehensiveLossbyComponentNetofTaxDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/OTHERCOMPREHENSIVELOSSChangesinAccumulatedOtherComprehensiveLossbyComponentNetofTaxDetails" xlink:type="extended" id="i9e0253b99b07473d869c11d1397af44b_OTHERCOMPREHENSIVELOSSChangesinAccumulatedOtherComprehensiveLossbyComponentNetofTaxDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_0d4d6175-934d-4f09-8a89-5763dbf4de5f" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_ad6e428f-8230-4fe7-8b25-991d17e2d934" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AOCIAttributableToParentNetOfTaxRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_0d4d6175-934d-4f09-8a89-5763dbf4de5f" xlink:to="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_ad6e428f-8230-4fe7-8b25-991d17e2d934" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_ef39941a-3a1c-41e5-8f44-060d4b15df24" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_ad6e428f-8230-4fe7-8b25-991d17e2d934" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_ef39941a-3a1c-41e5-8f44-060d4b15df24" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax_6f724825-231f-4f9f-bf32-e456adf4bcc9" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_ad6e428f-8230-4fe7-8b25-991d17e2d934" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax_6f724825-231f-4f9f-bf32-e456adf4bcc9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax_a7945e8c-0ffb-4927-9c1b-12317fb95351" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_ad6e428f-8230-4fe7-8b25-991d17e2d934" xlink:to="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax_a7945e8c-0ffb-4927-9c1b-12317fb95351" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_3ff6ec6c-87a7-417b-992e-8a5da8ce9cc9" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_ad6e428f-8230-4fe7-8b25-991d17e2d934" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_3ff6ec6c-87a7-417b-992e-8a5da8ce9cc9" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_9331f66a-1926-49cc-a1e7-b98bad1e428b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_38bbf2eb-8f5f-4842-9b37-cd66453dcf49" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_0d4d6175-934d-4f09-8a89-5763dbf4de5f" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_38bbf2eb-8f5f-4842-9b37-cd66453dcf49" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_af07fa20-6d4d-425c-8e71-d50988cc2b57" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_38bbf2eb-8f5f-4842-9b37-cd66453dcf49" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_af07fa20-6d4d-425c-8e71-d50988cc2b57" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_af07fa20-6d4d-425c-8e71-d50988cc2b57_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_af07fa20-6d4d-425c-8e71-d50988cc2b57" xlink:to="loc_us-gaap_EquityComponentDomain_af07fa20-6d4d-425c-8e71-d50988cc2b57_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_dc542348-889c-4624-aa71-2a92c5d7ebbf" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_af07fa20-6d4d-425c-8e71-d50988cc2b57" xlink:to="loc_us-gaap_EquityComponentDomain_dc542348-889c-4624-aa71-2a92c5d7ebbf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedTranslationAdjustmentMember_9df9bc41-9a61-468b-945f-a5c35d7ff0e2" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccumulatedTranslationAdjustmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_dc542348-889c-4624-aa71-2a92c5d7ebbf" xlink:to="loc_us-gaap_AccumulatedTranslationAdjustmentMember_9df9bc41-9a61-468b-945f-a5c35d7ff0e2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember_6eb90f26-f57b-4161-98fb-19f4588818c5" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_dc542348-889c-4624-aa71-2a92c5d7ebbf" xlink:to="loc_us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember_6eb90f26-f57b-4161-98fb-19f4588818c5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember_edf4fe69-8de6-45eb-912d-e355be922117" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_dc542348-889c-4624-aa71-2a92c5d7ebbf" xlink:to="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember_edf4fe69-8de6-45eb-912d-e355be922117" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_859d69f3-f443-4555-b0cb-d625339f095c" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_dc542348-889c-4624-aa71-2a92c5d7ebbf" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_859d69f3-f443-4555-b0cb-d625339f095c" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/OTHERCOMPREHENSIVELOSSReclassificationsOutofAccumulatedOtherComprehensiveLossDetails" xlink:type="simple" xlink:href="wab-20201231.xsd#OTHERCOMPREHENSIVELOSSReclassificationsOutofAccumulatedOtherComprehensiveLossDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/OTHERCOMPREHENSIVELOSSReclassificationsOutofAccumulatedOtherComprehensiveLossDetails" xlink:type="extended" id="id2516b4adf2c40ea9738dac01eca3960_OTHERCOMPREHENSIVELOSSReclassificationsOutofAccumulatedOtherComprehensiveLossDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationAdjustmentOutOfAccumulatedOtherComprehensiveIncomeOnDerivativesLineItems_63eb3ae8-9ab9-4e98-a958-14cc3ccd5a1d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ReclassificationAdjustmentOutOfAccumulatedOtherComprehensiveIncomeOnDerivativesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherOperatingIncomeExpenseNet_54663364-61e3-417b-a2cc-645ed16eab5e" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherOperatingIncomeExpenseNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationAdjustmentOutOfAccumulatedOtherComprehensiveIncomeOnDerivativesLineItems_63eb3ae8-9ab9-4e98-a958-14cc3ccd5a1d" xlink:to="loc_us-gaap_OtherOperatingIncomeExpenseNet_54663364-61e3-417b-a2cc-645ed16eab5e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_d1dd59f7-3594-409f-bc79-ac559c061604" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeTaxExpenseBenefit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationAdjustmentOutOfAccumulatedOtherComprehensiveIncomeOnDerivativesLineItems_63eb3ae8-9ab9-4e98-a958-14cc3ccd5a1d" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_d1dd59f7-3594-409f-bc79-ac559c061604" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_bbf69f04-83d9-4a07-92aa-9e934c94a818" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationAdjustmentOutOfAccumulatedOtherComprehensiveIncomeOnDerivativesLineItems_63eb3ae8-9ab9-4e98-a958-14cc3ccd5a1d" xlink:to="loc_us-gaap_NetIncomeLoss_bbf69f04-83d9-4a07-92aa-9e934c94a818" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeTable_e87cb059-c71e-4573-a9b0-5a583bd1d5c5" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ReclassificationAdjustmentOutOfAccumulatedOtherComprehensiveIncomeOnDerivativesLineItems_63eb3ae8-9ab9-4e98-a958-14cc3ccd5a1d" xlink:to="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeTable_e87cb059-c71e-4573-a9b0-5a583bd1d5c5" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeAxis_2b04dc28-88fb-4030-9012-db8d569e38e5" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeTable_e87cb059-c71e-4573-a9b0-5a583bd1d5c5" xlink:to="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeAxis_2b04dc28-88fb-4030-9012-db8d569e38e5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeDomain_2b04dc28-88fb-4030-9012-db8d569e38e5_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeAxis_2b04dc28-88fb-4030-9012-db8d569e38e5" xlink:to="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeDomain_2b04dc28-88fb-4030-9012-db8d569e38e5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeDomain_c58b6610-29d6-4856-8276-d14c0797d091" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeAxis_2b04dc28-88fb-4030-9012-db8d569e38e5" xlink:to="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeDomain_c58b6610-29d6-4856-8276-d14c0797d091" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMember_d2b1d794-681f-45cf-9cfc-c198ab320955" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeDomain_c58b6610-29d6-4856-8276-d14c0797d091" xlink:to="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeMember_d2b1d794-681f-45cf-9cfc-c198ab320955" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_f2d4eb12-8dbb-4065-815f-69db60606f3f" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ReclassificationOutOfAccumulatedOtherComprehensiveIncomeTable_e87cb059-c71e-4573-a9b0-5a583bd1d5c5" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_f2d4eb12-8dbb-4065-815f-69db60606f3f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_f2d4eb12-8dbb-4065-815f-69db60606f3f_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_f2d4eb12-8dbb-4065-815f-69db60606f3f" xlink:to="loc_us-gaap_EquityComponentDomain_f2d4eb12-8dbb-4065-815f-69db60606f3f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_c051ef56-12eb-4ba7-95fc-3c89a08b6dcb" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_f2d4eb12-8dbb-4065-815f-69db60606f3f" xlink:to="loc_us-gaap_EquityComponentDomain_c051ef56-12eb-4ba7-95fc-3c89a08b6dcb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentNetPriorServiceCostCreditMember_fd2fb203-c715-4fc8-8234-dfb4cd1b172f" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccumulatedDefinedBenefitPlansAdjustmentNetPriorServiceCostCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_c051ef56-12eb-4ba7-95fc-3c89a08b6dcb" xlink:to="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentNetPriorServiceCostCreditMember_fd2fb203-c715-4fc8-8234-dfb4cd1b172f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentNetUnamortizedGainLossMember_32f9bd0b-930a-4dae-8083-f91406ea304b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccumulatedDefinedBenefitPlansAdjustmentNetUnamortizedGainLossMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_c051ef56-12eb-4ba7-95fc-3c89a08b6dcb" xlink:to="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentNetUnamortizedGainLossMember_32f9bd0b-930a-4dae-8083-f91406ea304b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember_0ad0a684-658f-4487-a0af-a89e7a4b8fde" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_c051ef56-12eb-4ba7-95fc-3c89a08b6dcb" xlink:to="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember_0ad0a684-658f-4487-a0af-a89e7a4b8fde" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/LEASES" xlink:type="simple" xlink:href="wab-20201231.xsd#LEASES"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/LEASES" xlink:type="extended" id="i77862b6bebf547f695403595c13c8f1f_LEASES"/>
  <link:roleRef roleURI="http://wabtec.com/role/LEASESTables" xlink:type="simple" xlink:href="wab-20201231.xsd#LEASESTables"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/LEASESTables" xlink:type="extended" id="ic2b13e822fac43db9b83b5e8755a798b_LEASESTables"/>
  <link:roleRef roleURI="http://wabtec.com/role/LEASESNarrativeDetails" xlink:type="simple" xlink:href="wab-20201231.xsd#LEASESNarrativeDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/LEASESNarrativeDetails" xlink:type="extended" id="i959d57fae0f445239af50b3921ee555a_LEASESNarrativeDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeasedAssetsLineItems_f63296b1-f304-4dca-a735-e9ce2dcd35d5" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OperatingLeasedAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_LesseeWeightedAverageDiscountRatePercent_05ebc1c5-f98e-46bc-a147-6459e7803a3f" xlink:href="wab-20201231.xsd#wab_LesseeWeightedAverageDiscountRatePercent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingLeasedAssetsLineItems_f63296b1-f304-4dca-a735-e9ce2dcd35d5" xlink:to="loc_wab_LesseeWeightedAverageDiscountRatePercent_05ebc1c5-f98e-46bc-a147-6459e7803a3f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfOperatingLeasedAssetsTable_64e82514-bc90-4616-966e-3cef85aba2df" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfOperatingLeasedAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_OperatingLeasedAssetsLineItems_f63296b1-f304-4dca-a735-e9ce2dcd35d5" xlink:to="loc_us-gaap_ScheduleOfOperatingLeasedAssetsTable_64e82514-bc90-4616-966e-3cef85aba2df" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_d51500ae-3e73-48ea-b862-1e6bcc01e5f7" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfOperatingLeasedAssetsTable_64e82514-bc90-4616-966e-3cef85aba2df" xlink:to="loc_srt_RangeAxis_d51500ae-3e73-48ea-b862-1e6bcc01e5f7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_d51500ae-3e73-48ea-b862-1e6bcc01e5f7_default" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_d51500ae-3e73-48ea-b862-1e6bcc01e5f7" xlink:to="loc_srt_RangeMember_d51500ae-3e73-48ea-b862-1e6bcc01e5f7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_c056c43f-4f1c-4ade-854d-861fad99c19a" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_d51500ae-3e73-48ea-b862-1e6bcc01e5f7" xlink:to="loc_srt_RangeMember_c056c43f-4f1c-4ade-854d-861fad99c19a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_5f1b40cc-ddd9-437a-a316-b95e25021667" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_c056c43f-4f1c-4ade-854d-861fad99c19a" xlink:to="loc_srt_MinimumMember_5f1b40cc-ddd9-437a-a316-b95e25021667" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_02e1d79d-44eb-4b1b-b6b1-3e9ad2d04f02" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_c056c43f-4f1c-4ade-854d-861fad99c19a" xlink:to="loc_srt_MaximumMember_02e1d79d-44eb-4b1b-b6b1-3e9ad2d04f02" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/LEASESLeaseExpenseDetails" xlink:type="simple" xlink:href="wab-20201231.xsd#LEASESLeaseExpenseDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/LEASESLeaseExpenseDetails" xlink:type="extended" id="i009d1acf4bbb4dc58aa3606206bd8d7e_LEASESLeaseExpenseDetails"/>
  <link:roleRef roleURI="http://wabtec.com/role/LEASESMaturityofLeaseLiabilitiesDetails" xlink:type="simple" xlink:href="wab-20201231.xsd#LEASESMaturityofLeaseLiabilitiesDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/LEASESMaturityofLeaseLiabilitiesDetails" xlink:type="extended" id="i30af0eecaa4b4bcd96d20f0ff8d7f403_LEASESMaturityofLeaseLiabilitiesDetails"/>
  <link:roleRef roleURI="http://wabtec.com/role/LEASESLeaseTermandDiscountRateDetails" xlink:type="simple" xlink:href="wab-20201231.xsd#LEASESLeaseTermandDiscountRateDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/LEASESLeaseTermandDiscountRateDetails" xlink:type="extended" id="i453ae3dbe3ea414dbe5bb3b27fcafd39_LEASESLeaseTermandDiscountRateDetails"/>
  <link:roleRef roleURI="http://wabtec.com/role/WARRANTIES" xlink:type="simple" xlink:href="wab-20201231.xsd#WARRANTIES"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/WARRANTIES" xlink:type="extended" id="i3c11524a6d41487eb685c6b13b137751_WARRANTIES"/>
  <link:roleRef roleURI="http://wabtec.com/role/WARRANTIESTables" xlink:type="simple" xlink:href="wab-20201231.xsd#WARRANTIESTables"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/WARRANTIESTables" xlink:type="extended" id="iec66145b5bbf44d89f62803a963f163e_WARRANTIESTables"/>
  <link:roleRef roleURI="http://wabtec.com/role/WARRANTIESChangesinProductWarrantyReserveDetails" xlink:type="simple" xlink:href="wab-20201231.xsd#WARRANTIESChangesinProductWarrantyReserveDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/WARRANTIESChangesinProductWarrantyReserveDetails" xlink:type="extended" id="if5345be918ad49d0b90cd73fbae93c11_WARRANTIESChangesinProductWarrantyReserveDetails"/>
  <link:roleRef roleURI="http://wabtec.com/role/DERIVATIVEFINANCIALINSTRUMENTSANDHEDGING" xlink:type="simple" xlink:href="wab-20201231.xsd#DERIVATIVEFINANCIALINSTRUMENTSANDHEDGING"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/DERIVATIVEFINANCIALINSTRUMENTSANDHEDGING" xlink:type="extended" id="i2bce53ea4cc24c78bee7bd0417e52172_DERIVATIVEFINANCIALINSTRUMENTSANDHEDGING"/>
  <link:roleRef roleURI="http://wabtec.com/role/DERIVATIVEFINANCIALINSTRUMENTSANDHEDGINGTables" xlink:type="simple" xlink:href="wab-20201231.xsd#DERIVATIVEFINANCIALINSTRUMENTSANDHEDGINGTables"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/DERIVATIVEFINANCIALINSTRUMENTSANDHEDGINGTables" xlink:type="extended" id="i4cc5daeffd174a3db9563f47e69b5285_DERIVATIVEFINANCIALINSTRUMENTSANDHEDGINGTables"/>
  <link:roleRef roleURI="http://wabtec.com/role/DERIVATIVEFINANCIALINSTRUMENTSANDHEDGINGNarrativeDetails" xlink:type="simple" xlink:href="wab-20201231.xsd#DERIVATIVEFINANCIALINSTRUMENTSANDHEDGINGNarrativeDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/DERIVATIVEFINANCIALINSTRUMENTSANDHEDGINGNarrativeDetails" xlink:type="extended" id="i18106216c20b4ea098b5a173c8afa439_DERIVATIVEFINANCIALINSTRUMENTSANDHEDGINGNarrativeDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLineItems_acecd90c-19e3-4fd7-b2ca-1fb28b1bb197" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnrealizedGainLossOnDerivatives_2613b1a3-6b32-41a8-b72b-de56d73bf7aa" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_UnrealizedGainLossOnDerivatives"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_acecd90c-19e3-4fd7-b2ca-1fb28b1bb197" xlink:to="loc_us-gaap_UnrealizedGainLossOnDerivatives_2613b1a3-6b32-41a8-b72b-de56d73bf7aa" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeTermOfContract_5f920f9a-c2a1-4204-9cee-8087f4900d81" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeTermOfContract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_acecd90c-19e3-4fd7-b2ca-1fb28b1bb197" xlink:to="loc_us-gaap_DerivativeTermOfContract_5f920f9a-c2a1-4204-9cee-8087f4900d81" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeTable_a54e4acf-e20d-4b8e-ac9a-3bb7594304d0" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativeLineItems_acecd90c-19e3-4fd7-b2ca-1fb28b1bb197" xlink:to="loc_us-gaap_DerivativeTable_a54e4acf-e20d-4b8e-ac9a-3bb7594304d0" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationAxis_2a3af982-981c-493b-80b4-707661ffd3dc" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_HedgingDesignationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_a54e4acf-e20d-4b8e-ac9a-3bb7594304d0" xlink:to="loc_us-gaap_HedgingDesignationAxis_2a3af982-981c-493b-80b4-707661ffd3dc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_2a3af982-981c-493b-80b4-707661ffd3dc_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_HedgingDesignationAxis_2a3af982-981c-493b-80b4-707661ffd3dc" xlink:to="loc_us-gaap_HedgingDesignationDomain_2a3af982-981c-493b-80b4-707661ffd3dc_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_5f6cf753-c21b-4ca2-b01d-90fc17508b77" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_HedgingDesignationAxis_2a3af982-981c-493b-80b4-707661ffd3dc" xlink:to="loc_us-gaap_HedgingDesignationDomain_5f6cf753-c21b-4ca2-b01d-90fc17508b77" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NondesignatedMember_96ccbdae-bfa1-4080-a5a3-c45ab4bfa478" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NondesignatedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_5f6cf753-c21b-4ca2-b01d-90fc17508b77" xlink:to="loc_us-gaap_NondesignatedMember_96ccbdae-bfa1-4080-a5a3-c45ab4bfa478" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_091dffd9-386d-40b9-a234-e8e2b20af64d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_a54e4acf-e20d-4b8e-ac9a-3bb7594304d0" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_091dffd9-386d-40b9-a234-e8e2b20af64d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_091dffd9-386d-40b9-a234-e8e2b20af64d_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_091dffd9-386d-40b9-a234-e8e2b20af64d" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_091dffd9-386d-40b9-a234-e8e2b20af64d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_f7cfbfe1-b239-4ad5-9e77-f6ea70408052" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_091dffd9-386d-40b9-a234-e8e2b20af64d" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_f7cfbfe1-b239-4ad5-9e77-f6ea70408052" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignExchangeForwardMember_65b6320e-6909-48a2-9170-1e9e944442b8" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ForeignExchangeForwardMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_f7cfbfe1-b239-4ad5-9e77-f6ea70408052" xlink:to="loc_us-gaap_ForeignExchangeForwardMember_65b6320e-6909-48a2-9170-1e9e944442b8" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/DERIVATIVEFINANCIALINSTRUMENTSANDHEDGINGSummaryofNotionalAmountsandFairValueDetails" xlink:type="simple" xlink:href="wab-20201231.xsd#DERIVATIVEFINANCIALINSTRUMENTSANDHEDGINGSummaryofNotionalAmountsandFairValueDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/DERIVATIVEFINANCIALINSTRUMENTSANDHEDGINGSummaryofNotionalAmountsandFairValueDetails" xlink:type="extended" id="ibb8de15e534f41a3969353a0e6f04ec9_DERIVATIVEFINANCIALINSTRUMENTSANDHEDGINGSummaryofNotionalAmountsandFairValueDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLineItems_925857ed-0dc7-4bb5-b5c7-3724e10609ee" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeFairValueOfDerivativeAsset_fde19699-2b8b-4d53-aa56-44e04d87b6eb" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeFairValueOfDerivativeAsset"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_925857ed-0dc7-4bb5-b5c7-3724e10609ee" xlink:to="loc_us-gaap_DerivativeFairValueOfDerivativeAsset_fde19699-2b8b-4d53-aa56-44e04d87b6eb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeFairValueOfDerivativeLiability_04b24c98-7789-4084-854c-083115206d0e" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeFairValueOfDerivativeLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_925857ed-0dc7-4bb5-b5c7-3724e10609ee" xlink:to="loc_us-gaap_DerivativeFairValueOfDerivativeLiability_04b24c98-7789-4084-854c-083115206d0e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeFairValueOfDerivativeNet_968d9a7a-8991-4d4d-b54d-55236a5372da" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeFairValueOfDerivativeNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_925857ed-0dc7-4bb5-b5c7-3724e10609ee" xlink:to="loc_us-gaap_DerivativeFairValueOfDerivativeNet_968d9a7a-8991-4d4d-b54d-55236a5372da" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeNotionalAmount_4883ac76-93b5-4fc0-88f7-18f99276ee9e" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeNotionalAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_925857ed-0dc7-4bb5-b5c7-3724e10609ee" xlink:to="loc_us-gaap_DerivativeNotionalAmount_4883ac76-93b5-4fc0-88f7-18f99276ee9e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeTable_4ee27571-ea35-4634-8b82-95e6d2f2cd52" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativeLineItems_925857ed-0dc7-4bb5-b5c7-3724e10609ee" xlink:to="loc_us-gaap_DerivativeTable_4ee27571-ea35-4634-8b82-95e6d2f2cd52" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalanceSheetLocationAxis_b3912990-6092-4fce-91f0-37f2f15d7b86" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BalanceSheetLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_4ee27571-ea35-4634-8b82-95e6d2f2cd52" xlink:to="loc_us-gaap_BalanceSheetLocationAxis_b3912990-6092-4fce-91f0-37f2f15d7b86" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_b3912990-6092-4fce-91f0-37f2f15d7b86_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BalanceSheetLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_b3912990-6092-4fce-91f0-37f2f15d7b86" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_b3912990-6092-4fce-91f0-37f2f15d7b86_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_82e16113-8cf9-4ba3-88d4-21b7c2e70eb2" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BalanceSheetLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_b3912990-6092-4fce-91f0-37f2f15d7b86" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_82e16113-8cf9-4ba3-88d4-21b7c2e70eb2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherCurrentAssetsMember_b8013c11-f4ce-4348-ac14-b56d5d92391d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherCurrentAssetsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_82e16113-8cf9-4ba3-88d4-21b7c2e70eb2" xlink:to="loc_us-gaap_OtherCurrentAssetsMember_b8013c11-f4ce-4348-ac14-b56d5d92391d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherCurrentLiabilitiesMember_68465d46-0b5a-4ff1-baea-476b5671b300" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OtherCurrentLiabilitiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_82e16113-8cf9-4ba3-88d4-21b7c2e70eb2" xlink:to="loc_us-gaap_OtherCurrentLiabilitiesMember_68465d46-0b5a-4ff1-baea-476b5671b300" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationAxis_bb04345e-9acc-430b-bf22-9bc7713e2628" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_HedgingDesignationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_4ee27571-ea35-4634-8b82-95e6d2f2cd52" xlink:to="loc_us-gaap_HedgingDesignationAxis_bb04345e-9acc-430b-bf22-9bc7713e2628" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_bb04345e-9acc-430b-bf22-9bc7713e2628_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_HedgingDesignationAxis_bb04345e-9acc-430b-bf22-9bc7713e2628" xlink:to="loc_us-gaap_HedgingDesignationDomain_bb04345e-9acc-430b-bf22-9bc7713e2628_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_846a68a2-d59a-40c2-8334-1c614be48947" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_HedgingDesignationAxis_bb04345e-9acc-430b-bf22-9bc7713e2628" xlink:to="loc_us-gaap_HedgingDesignationDomain_846a68a2-d59a-40c2-8334-1c614be48947" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DesignatedAsHedgingInstrumentMember_db4eecaf-342a-40b1-967a-bdec270e0cbf" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DesignatedAsHedgingInstrumentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_846a68a2-d59a-40c2-8334-1c614be48947" xlink:to="loc_us-gaap_DesignatedAsHedgingInstrumentMember_db4eecaf-342a-40b1-967a-bdec270e0cbf" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NondesignatedMember_fe981a03-c4d2-42b0-99ce-b9afa832629b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_NondesignatedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_846a68a2-d59a-40c2-8334-1c614be48947" xlink:to="loc_us-gaap_NondesignatedMember_fe981a03-c4d2-42b0-99ce-b9afa832629b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_78740d5c-3f7e-4443-8f69-511a59954104" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_4ee27571-ea35-4634-8b82-95e6d2f2cd52" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_78740d5c-3f7e-4443-8f69-511a59954104" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_78740d5c-3f7e-4443-8f69-511a59954104_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_78740d5c-3f7e-4443-8f69-511a59954104" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_78740d5c-3f7e-4443-8f69-511a59954104_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_f6b85820-cc1e-4275-a502-363ec6e38d67" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_78740d5c-3f7e-4443-8f69-511a59954104" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_f6b85820-cc1e-4275-a502-363ec6e38d67" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignExchangeContractMember_c5e1b25b-f7b6-43e5-b3f5-89e3144005c5" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ForeignExchangeContractMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_f6b85820-cc1e-4275-a502-363ec6e38d67" xlink:to="loc_us-gaap_ForeignExchangeContractMember_c5e1b25b-f7b6-43e5-b3f5-89e3144005c5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CurrencySwapMember_137fb52f-4c6a-4cbb-83a6-366653bf419d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CurrencySwapMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_f6b85820-cc1e-4275-a502-363ec6e38d67" xlink:to="loc_us-gaap_CurrencySwapMember_137fb52f-4c6a-4cbb-83a6-366653bf419d" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/FAIRVALUEMEASUREMENTANDFAIRVALUEOFFINANCIALINSTRUMENTS" xlink:type="simple" xlink:href="wab-20201231.xsd#FAIRVALUEMEASUREMENTANDFAIRVALUEOFFINANCIALINSTRUMENTS"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/FAIRVALUEMEASUREMENTANDFAIRVALUEOFFINANCIALINSTRUMENTS" xlink:type="extended" id="ia5ef978e554f49b49d5e9a4fe1dee76b_FAIRVALUEMEASUREMENTANDFAIRVALUEOFFINANCIALINSTRUMENTS"/>
  <link:roleRef roleURI="http://wabtec.com/role/FAIRVALUEMEASUREMENTANDFAIRVALUEOFFINANCIALINSTRUMENTSTables" xlink:type="simple" xlink:href="wab-20201231.xsd#FAIRVALUEMEASUREMENTANDFAIRVALUEOFFINANCIALINSTRUMENTSTables"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/FAIRVALUEMEASUREMENTANDFAIRVALUEOFFINANCIALINSTRUMENTSTables" xlink:type="extended" id="if785e330f79544bfbbd3ab17ef2e7d33_FAIRVALUEMEASUREMENTANDFAIRVALUEOFFINANCIALINSTRUMENTSTables"/>
  <link:roleRef roleURI="http://wabtec.com/role/FAIRVALUEMEASUREMENTANDFAIRVALUEOFFINANCIALINSTRUMENTSLiabilitiesCarriedatFairValueMeasuredonRecurringBasisDetails" xlink:type="simple" xlink:href="wab-20201231.xsd#FAIRVALUEMEASUREMENTANDFAIRVALUEOFFINANCIALINSTRUMENTSLiabilitiesCarriedatFairValueMeasuredonRecurringBasisDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/FAIRVALUEMEASUREMENTANDFAIRVALUEOFFINANCIALINSTRUMENTSLiabilitiesCarriedatFairValueMeasuredonRecurringBasisDetails" xlink:type="extended" id="icedbcf37a5bf4dd98f3040b05ece0c34_FAIRVALUEMEASUREMENTANDFAIRVALUEOFFINANCIALINSTRUMENTSLiabilitiesCarriedatFairValueMeasuredonRecurringBasisDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_615d0696-198e-4691-b943-f1b78bea20de" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeAssets_8a2f512e-244f-422e-9207-5bdb5e07f2cc" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_615d0696-198e-4691-b943-f1b78bea20de" xlink:to="loc_us-gaap_DerivativeAssets_8a2f512e-244f-422e-9207-5bdb5e07f2cc" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLiabilities_d002e773-3f18-4b57-9ac9-bca074e65e66" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_615d0696-198e-4691-b943-f1b78bea20de" xlink:to="loc_us-gaap_DerivativeLiabilities_d002e773-3f18-4b57-9ac9-bca074e65e66" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_5f32b72c-e6c6-4091-ab15-47516864c2f6" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems_615d0696-198e-4691-b943-f1b78bea20de" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_5f32b72c-e6c6-4091-ab15-47516864c2f6" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_e2edf715-c791-42df-9f37-5fc69c11052b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_5f32b72c-e6c6-4091-ab15-47516864c2f6" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_e2edf715-c791-42df-9f37-5fc69c11052b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_e2edf715-c791-42df-9f37-5fc69c11052b_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_e2edf715-c791-42df-9f37-5fc69c11052b" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_e2edf715-c791-42df-9f37-5fc69c11052b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_7f8b313a-efc8-4f39-8f21-8ba46e11fea0" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_e2edf715-c791-42df-9f37-5fc69c11052b" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_7f8b313a-efc8-4f39-8f21-8ba46e11fea0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_8982193d-8581-46d9-a909-a32b7138345b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueInputsLevel1Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_7f8b313a-efc8-4f39-8f21-8ba46e11fea0" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_8982193d-8581-46d9-a909-a32b7138345b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_485d59f0-41c9-420b-87dd-0659cabf0c96" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_7f8b313a-efc8-4f39-8f21-8ba46e11fea0" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_485d59f0-41c9-420b-87dd-0659cabf0c96" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_dd61ffdd-afc9-44c6-a9bc-2edd199d44ea" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_7f8b313a-efc8-4f39-8f21-8ba46e11fea0" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_dd61ffdd-afc9-44c6-a9bc-2edd199d44ea" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_8cdb7a80-c776-4e76-aa87-9f26ad22a741" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_5f32b72c-e6c6-4091-ab15-47516864c2f6" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_8cdb7a80-c776-4e76-aa87-9f26ad22a741" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_8cdb7a80-c776-4e76-aa87-9f26ad22a741_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_8cdb7a80-c776-4e76-aa87-9f26ad22a741" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_8cdb7a80-c776-4e76-aa87-9f26ad22a741_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_48d01465-a466-4b95-814c-0b9f49d02c6e" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_8cdb7a80-c776-4e76-aa87-9f26ad22a741" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_48d01465-a466-4b95-814c-0b9f49d02c6e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignExchangeContractMember_1e508229-3899-49d1-a03e-cf404a6ed24c" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ForeignExchangeContractMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_48d01465-a466-4b95-814c-0b9f49d02c6e" xlink:to="loc_us-gaap_ForeignExchangeContractMember_1e508229-3899-49d1-a03e-cf404a6ed24c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CurrencySwapMember_20681ccb-213f-4ce6-b08c-680278d8105e" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_CurrencySwapMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_48d01465-a466-4b95-814c-0b9f49d02c6e" xlink:to="loc_us-gaap_CurrencySwapMember_20681ccb-213f-4ce6-b08c-680278d8105e" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/FAIRVALUEMEASUREMENTANDFAIRVALUEOFFINANCIALINSTRUMENTSNarrativeDetails" xlink:type="simple" xlink:href="wab-20201231.xsd#FAIRVALUEMEASUREMENTANDFAIRVALUEOFFINANCIALINSTRUMENTSNarrativeDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/FAIRVALUEMEASUREMENTANDFAIRVALUEOFFINANCIALINSTRUMENTSNarrativeDetails" xlink:type="extended" id="i08b6cd237399453e8fefe36b5821d180_FAIRVALUEMEASUREMENTANDFAIRVALUEOFFINANCIALINSTRUMENTSNarrativeDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_8132b6a2-c101-4d6e-acf4-cf250008c16a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationLiability_48043dc0-0366-4273-89e1-6864b395904c" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessCombinationContingentConsiderationLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_8132b6a2-c101-4d6e-acf4-cf250008c16a" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationLiability_48043dc0-0366-4273-89e1-6864b395904c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProductWarrantyAccrualNoncurrent_a2f30ae5-14ee-414c-a6dd-2ea7c258d471" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ProductWarrantyAccrualNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_8132b6a2-c101-4d6e-acf4-cf250008c16a" xlink:to="loc_us-gaap_ProductWarrantyAccrualNoncurrent_a2f30ae5-14ee-414c-a6dd-2ea7c258d471" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_ca43141f-2d52-4aa3-a121-92a8d5dfdf0d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_8132b6a2-c101-4d6e-acf4-cf250008c16a" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_ca43141f-2d52-4aa3-a121-92a8d5dfdf0d" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalanceSheetLocationAxis_e68c444c-8bc4-40ff-b482-d41eb7998f4c" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BalanceSheetLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_ca43141f-2d52-4aa3-a121-92a8d5dfdf0d" xlink:to="loc_us-gaap_BalanceSheetLocationAxis_e68c444c-8bc4-40ff-b482-d41eb7998f4c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_e68c444c-8bc4-40ff-b482-d41eb7998f4c_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BalanceSheetLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_e68c444c-8bc4-40ff-b482-d41eb7998f4c" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_e68c444c-8bc4-40ff-b482-d41eb7998f4c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_9e5a048e-13be-48ef-9731-dfeaee1c5731" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BalanceSheetLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_e68c444c-8bc4-40ff-b482-d41eb7998f4c" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_9e5a048e-13be-48ef-9731-dfeaee1c5731" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_OtherAccruedLiabilitiesMember_6d6e6d35-d724-4067-a5bd-38f30bfd570f" xlink:href="wab-20201231.xsd#wab_OtherAccruedLiabilitiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_9e5a048e-13be-48ef-9731-dfeaee1c5731" xlink:to="loc_wab_OtherAccruedLiabilitiesMember_6d6e6d35-d724-4067-a5bd-38f30bfd570f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_ca3445ea-fbe2-4987-8781-e7d37bfe5f8f" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_ca43141f-2d52-4aa3-a121-92a8d5dfdf0d" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_ca3445ea-fbe2-4987-8781-e7d37bfe5f8f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_ca3445ea-fbe2-4987-8781-e7d37bfe5f8f_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_ca3445ea-fbe2-4987-8781-e7d37bfe5f8f" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_ca3445ea-fbe2-4987-8781-e7d37bfe5f8f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_c5672d18-eba6-4f1c-b24f-47552f789fff" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_ca3445ea-fbe2-4987-8781-e7d37bfe5f8f" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_c5672d18-eba6-4f1c-b24f-47552f789fff" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_GeneralElectricCompanyMember_82de8a2b-b87e-4eec-8949-1fc040685b49" xlink:href="wab-20201231.xsd#wab_GeneralElectricCompanyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_c5672d18-eba6-4f1c-b24f-47552f789fff" xlink:to="loc_wab_GeneralElectricCompanyMember_82de8a2b-b87e-4eec-8949-1fc040685b49" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_6d0b52d8-531d-4523-ad34-904e38f4458a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_ca43141f-2d52-4aa3-a121-92a8d5dfdf0d" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_6d0b52d8-531d-4523-ad34-904e38f4458a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_6d0b52d8-531d-4523-ad34-904e38f4458a_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_6d0b52d8-531d-4523-ad34-904e38f4458a" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_6d0b52d8-531d-4523-ad34-904e38f4458a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_f95c8eae-f7e1-4f91-b50d-f129f978308c" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_6d0b52d8-531d-4523-ad34-904e38f4458a" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_f95c8eae-f7e1-4f91-b50d-f129f978308c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_b55a9baf-be04-4c63-865c-462e3bbe90e8" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_f95c8eae-f7e1-4f91-b50d-f129f978308c" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_b55a9baf-be04-4c63-865c-462e3bbe90e8" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/COMMITMENTSANDCONTINGENCIES" xlink:type="simple" xlink:href="wab-20201231.xsd#COMMITMENTSANDCONTINGENCIES"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/COMMITMENTSANDCONTINGENCIES" xlink:type="extended" id="i868f2f1c07cc4eaf875d2f73a2172f0c_COMMITMENTSANDCONTINGENCIES"/>
  <link:roleRef roleURI="http://wabtec.com/role/COMMITMENTSANDCONTINGENCIESNarrativeDetails" xlink:type="simple" xlink:href="wab-20201231.xsd#COMMITMENTSANDCONTINGENCIESNarrativeDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/COMMITMENTSANDCONTINGENCIESNarrativeDetails" xlink:type="extended" id="i10d6830ae62a4522849eb1789aa726b3_COMMITMENTSANDCONTINGENCIESNarrativeDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingenciesLineItems_b82a2585-2eac-4e89-bdde-185d5bc531f5" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LossContingenciesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyDamagesSoughtValue_b3123e65-89f7-4c9a-85aa-a7aec5a8a2b4" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LossContingencyDamagesSoughtValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_b82a2585-2eac-4e89-bdde-185d5bc531f5" xlink:to="loc_us-gaap_LossContingencyDamagesSoughtValue_b3123e65-89f7-4c9a-85aa-a7aec5a8a2b4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyPendingClaimsNumber_fdb043f6-b98f-4b86-ad62-c3e1b610c362" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LossContingencyPendingClaimsNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_b82a2585-2eac-4e89-bdde-185d5bc531f5" xlink:to="loc_us-gaap_LossContingencyPendingClaimsNumber_fdb043f6-b98f-4b86-ad62-c3e1b610c362" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingenciesTable_aa709fb2-52bc-42b7-9f7e-dcf8bb5dcc01" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LossContingenciesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LossContingenciesLineItems_b82a2585-2eac-4e89-bdde-185d5bc531f5" xlink:to="loc_us-gaap_LossContingenciesTable_aa709fb2-52bc-42b7-9f7e-dcf8bb5dcc01" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LitigationStatusAxis_111d35d6-cd85-4677-a66d-fa10d8ac1e1c" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LitigationStatusAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_aa709fb2-52bc-42b7-9f7e-dcf8bb5dcc01" xlink:to="loc_us-gaap_LitigationStatusAxis_111d35d6-cd85-4677-a66d-fa10d8ac1e1c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LitigationStatusDomain_111d35d6-cd85-4677-a66d-fa10d8ac1e1c_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LitigationStatusDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LitigationStatusAxis_111d35d6-cd85-4677-a66d-fa10d8ac1e1c" xlink:to="loc_us-gaap_LitigationStatusDomain_111d35d6-cd85-4677-a66d-fa10d8ac1e1c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LitigationStatusDomain_dce08187-b0e7-44d9-a674-d13c5ecb7232" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_LitigationStatusDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LitigationStatusAxis_111d35d6-cd85-4677-a66d-fa10d8ac1e1c" xlink:to="loc_us-gaap_LitigationStatusDomain_dce08187-b0e7-44d9-a674-d13c5ecb7232" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ThreatenedLitigationMember_60b80531-7ef8-4744-8808-f327040b9b40" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ThreatenedLitigationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LitigationStatusDomain_dce08187-b0e7-44d9-a674-d13c5ecb7232" xlink:to="loc_us-gaap_ThreatenedLitigationMember_60b80531-7ef8-4744-8808-f327040b9b40" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PendingLitigationMember_34ed4d0d-838a-4463-8314-40a0d7e82c41" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PendingLitigationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LitigationStatusDomain_dce08187-b0e7-44d9-a674-d13c5ecb7232" xlink:to="loc_us-gaap_PendingLitigationMember_34ed4d0d-838a-4463-8314-40a0d7e82c41" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_LitigationCaseAxis_8c8d8ec7-4e7f-4392-873c-9ade6acb8703" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_LitigationCaseAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_aa709fb2-52bc-42b7-9f7e-dcf8bb5dcc01" xlink:to="loc_srt_LitigationCaseAxis_8c8d8ec7-4e7f-4392-873c-9ade6acb8703" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_LitigationCaseTypeDomain_8c8d8ec7-4e7f-4392-873c-9ade6acb8703_default" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_LitigationCaseTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_LitigationCaseAxis_8c8d8ec7-4e7f-4392-873c-9ade6acb8703" xlink:to="loc_srt_LitigationCaseTypeDomain_8c8d8ec7-4e7f-4392-873c-9ade6acb8703_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_LitigationCaseTypeDomain_31c42c2e-935d-4d6d-993d-479bf108502f" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_LitigationCaseTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_LitigationCaseAxis_8c8d8ec7-4e7f-4392-873c-9ade6acb8703" xlink:to="loc_srt_LitigationCaseTypeDomain_31c42c2e-935d-4d6d-993d-479bf108502f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_DenverTransitInstallationofConstantWirelessCrossingsMember_6fb1c6ad-001c-4e64-9f2d-8e1b10c88137" xlink:href="wab-20201231.xsd#wab_DenverTransitInstallationofConstantWirelessCrossingsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_LitigationCaseTypeDomain_31c42c2e-935d-4d6d-993d-479bf108502f" xlink:to="loc_wab_DenverTransitInstallationofConstantWirelessCrossingsMember_6fb1c6ad-001c-4e64-9f2d-8e1b10c88137" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesAxis_370a093f-15d7-4316-9722-33847136e7d8" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ConsolidatedEntitiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_aa709fb2-52bc-42b7-9f7e-dcf8bb5dcc01" xlink:to="loc_srt_ConsolidatedEntitiesAxis_370a093f-15d7-4316-9722-33847136e7d8" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_370a093f-15d7-4316-9722-33847136e7d8_default" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidatedEntitiesAxis_370a093f-15d7-4316-9722-33847136e7d8" xlink:to="loc_srt_ConsolidatedEntitiesDomain_370a093f-15d7-4316-9722-33847136e7d8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_74a5b15c-22ca-41e4-a839-8e48de732938" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidatedEntitiesAxis_370a093f-15d7-4316-9722-33847136e7d8" xlink:to="loc_srt_ConsolidatedEntitiesDomain_74a5b15c-22ca-41e4-a839-8e48de732938" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SubsidiariesMember_8d77aed6-08bc-449e-a79e-8a3fe0376a34" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_SubsidiariesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_74a5b15c-22ca-41e4-a839-8e48de732938" xlink:to="loc_srt_SubsidiariesMember_8d77aed6-08bc-449e-a79e-8a3fe0376a34" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/SEGMENTINFORMATION" xlink:type="simple" xlink:href="wab-20201231.xsd#SEGMENTINFORMATION"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/SEGMENTINFORMATION" xlink:type="extended" id="i7a856fc43a6e4a01930e503d3c5b265d_SEGMENTINFORMATION"/>
  <link:roleRef roleURI="http://wabtec.com/role/SEGMENTINFORMATIONTables" xlink:type="simple" xlink:href="wab-20201231.xsd#SEGMENTINFORMATIONTables"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/SEGMENTINFORMATIONTables" xlink:type="extended" id="ie3169ab2e78c424993d8c1052603e3d8_SEGMENTINFORMATIONTables"/>
  <link:roleRef roleURI="http://wabtec.com/role/SEGMENTINFORMATIONNarrativeDetails" xlink:type="simple" xlink:href="wab-20201231.xsd#SEGMENTINFORMATIONNarrativeDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/SEGMENTINFORMATIONNarrativeDetails" xlink:type="extended" id="i3a1e4095dd2243899413124a80dbe892_SEGMENTINFORMATIONNarrativeDetails"/>
  <link:roleRef roleURI="http://wabtec.com/role/SEGMENTINFORMATIONSegmentFinancialInformationDetails" xlink:type="simple" xlink:href="wab-20201231.xsd#SEGMENTINFORMATIONSegmentFinancialInformationDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/SEGMENTINFORMATIONSegmentFinancialInformationDetails" xlink:type="extended" id="i468dc5db7593489fa91634d7d369403c_SEGMENTINFORMATIONSegmentFinancialInformationDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_afdc0504-087e-4184-a905-6add6291411a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SegmentReportingInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_e65981b7-8712-4e31-9eac-bf209f54683b" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_afdc0504-087e-4184-a905-6add6291411a" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_e65981b7-8712-4e31-9eac-bf209f54683b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingIncomeLoss_d93240af-88f1-474e-9965-0bf1cb863e35" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OperatingIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_afdc0504-087e-4184-a905-6add6291411a" xlink:to="loc_us-gaap_OperatingIncomeLoss_d93240af-88f1-474e-9965-0bf1cb863e35" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_InterestExpenseAndOtherNet_9fa4408c-73fd-4cc7-8267-5e0d1ffa62f1" xlink:href="wab-20201231.xsd#wab_InterestExpenseAndOtherNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_afdc0504-087e-4184-a905-6add6291411a" xlink:to="loc_wab_InterestExpenseAndOtherNet_9fa4408c-73fd-4cc7-8267-5e0d1ffa62f1" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_3e053c3e-7adb-446c-9ea1-5cf630cd3ee4" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_afdc0504-087e-4184-a905-6add6291411a" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_3e053c3e-7adb-446c-9ea1-5cf630cd3ee4" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepreciationAndAmortization_73b48b5b-0485-4a6d-bb70-216c254e5e5e" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_DepreciationAndAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_afdc0504-087e-4184-a905-6add6291411a" xlink:to="loc_us-gaap_DepreciationAndAmortization_73b48b5b-0485-4a6d-bb70-216c254e5e5e" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_c0117991-dfc1-46c7-8b49-028a740a22fe" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PaymentsToAcquirePropertyPlantAndEquipment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_afdc0504-087e-4184-a905-6add6291411a" xlink:to="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_c0117991-dfc1-46c7-8b49-028a740a22fe" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Assets_9eb20925-2d70-40f4-b9da-e55d01d3f753" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_Assets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_afdc0504-087e-4184-a905-6add6291411a" xlink:to="loc_us-gaap_Assets_9eb20925-2d70-40f4-b9da-e55d01d3f753" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_37b19d4a-9b2a-4d70-8691-2ddfe0c8e3c3" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_afdc0504-087e-4184-a905-6add6291411a" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_37b19d4a-9b2a-4d70-8691-2ddfe0c8e3c3" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis_3a8fb344-b9fd-4669-aaa1-07e35950f4f7" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ConsolidationItemsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_37b19d4a-9b2a-4d70-8691-2ddfe0c8e3c3" xlink:to="loc_srt_ConsolidationItemsAxis_3a8fb344-b9fd-4669-aaa1-07e35950f4f7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_3a8fb344-b9fd-4669-aaa1-07e35950f4f7_default" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_3a8fb344-b9fd-4669-aaa1-07e35950f4f7" xlink:to="loc_srt_ConsolidationItemsDomain_3a8fb344-b9fd-4669-aaa1-07e35950f4f7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_0014b48a-14b0-4a5f-919b-19dcad7e0004" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_3a8fb344-b9fd-4669-aaa1-07e35950f4f7" xlink:to="loc_srt_ConsolidationItemsDomain_0014b48a-14b0-4a5f-919b-19dcad7e0004" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingSegmentsMember_e18844f7-a4a6-40d1-932e-96b669099f6d" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_OperatingSegmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_0014b48a-14b0-4a5f-919b-19dcad7e0004" xlink:to="loc_us-gaap_OperatingSegmentsMember_e18844f7-a4a6-40d1-932e-96b669099f6d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_CorporateAndEliminationsMember_1d18f78c-d68e-47cb-bba1-e917616897a5" xlink:href="wab-20201231.xsd#wab_CorporateAndEliminationsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_0014b48a-14b0-4a5f-919b-19dcad7e0004" xlink:to="loc_wab_CorporateAndEliminationsMember_1d18f78c-d68e-47cb-bba1-e917616897a5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_8d632ce5-3ecb-4de5-b27b-c75c1e8ba1a9" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_37b19d4a-9b2a-4d70-8691-2ddfe0c8e3c3" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_8d632ce5-3ecb-4de5-b27b-c75c1e8ba1a9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_8d632ce5-3ecb-4de5-b27b-c75c1e8ba1a9_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_8d632ce5-3ecb-4de5-b27b-c75c1e8ba1a9" xlink:to="loc_us-gaap_SegmentDomain_8d632ce5-3ecb-4de5-b27b-c75c1e8ba1a9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_814f038a-5648-442c-a784-e9fa95ff6f77" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_8d632ce5-3ecb-4de5-b27b-c75c1e8ba1a9" xlink:to="loc_us-gaap_SegmentDomain_814f038a-5648-442c-a784-e9fa95ff6f77" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_FreightSegmentMember_939e30ca-0652-4499-9b36-63f53b0f617b" xlink:href="wab-20201231.xsd#wab_FreightSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_814f038a-5648-442c-a784-e9fa95ff6f77" xlink:to="loc_wab_FreightSegmentMember_939e30ca-0652-4499-9b36-63f53b0f617b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_TransitSegmentMember_90d0a5d3-d0be-4199-a4cb-68fc8261c1f8" xlink:href="wab-20201231.xsd#wab_TransitSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_814f038a-5648-442c-a784-e9fa95ff6f77" xlink:to="loc_wab_TransitSegmentMember_90d0a5d3-d0be-4199-a4cb-68fc8261c1f8" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/SEGMENTINFORMATIONGeographicAreaDataDetails" xlink:type="simple" xlink:href="wab-20201231.xsd#SEGMENTINFORMATIONGeographicAreaDataDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/SEGMENTINFORMATIONGeographicAreaDataDetails" xlink:type="extended" id="i7cffd457aea7435599d40da31d3a27cb_SEGMENTINFORMATIONGeographicAreaDataDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_8f237436-52b7-48e0-a653-eff2902f610f" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_049aed15-d955-4513-a077-840b61a9bf1a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_8f237436-52b7-48e0-a653-eff2902f610f" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_049aed15-d955-4513-a077-840b61a9bf1a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_599bbcbf-135a-45a5-9313-0058d86ef3e5" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_8f237436-52b7-48e0-a653-eff2902f610f" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_599bbcbf-135a-45a5-9313-0058d86ef3e5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_a8b7e794-45b9-43fd-8ba9-2c1a93bfb9e2" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_8f237436-52b7-48e0-a653-eff2902f610f" xlink:to="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_a8b7e794-45b9-43fd-8ba9-2c1a93bfb9e2" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis_6e96ef3f-b912-4801-aeef-a650106fd49d" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_StatementGeographicalAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_a8b7e794-45b9-43fd-8ba9-2c1a93bfb9e2" xlink:to="loc_srt_StatementGeographicalAxis_6e96ef3f-b912-4801-aeef-a650106fd49d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_6e96ef3f-b912-4801-aeef-a650106fd49d_default" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_6e96ef3f-b912-4801-aeef-a650106fd49d" xlink:to="loc_srt_SegmentGeographicalDomain_6e96ef3f-b912-4801-aeef-a650106fd49d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_8fcec98f-63ac-4aa7-9619-6baed9b240c2" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_6e96ef3f-b912-4801-aeef-a650106fd49d" xlink:to="loc_srt_SegmentGeographicalDomain_8fcec98f-63ac-4aa7-9619-6baed9b240c2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_NorthAmericaMember_0d5f83e4-cba3-4d93-8a29-c941016f4edb" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_NorthAmericaMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_8fcec98f-63ac-4aa7-9619-6baed9b240c2" xlink:to="loc_srt_NorthAmericaMember_0d5f83e4-cba3-4d93-8a29-c941016f4edb" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_US_94d5bd4c-f128-46b9-9f9f-e3399c6a69a8" xlink:href="https://xbrl.sec.gov/country/2020/country-2020-01-31.xsd#country_US"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NorthAmericaMember_0d5f83e4-cba3-4d93-8a29-c941016f4edb" xlink:to="loc_country_US_94d5bd4c-f128-46b9-9f9f-e3399c6a69a8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_CA_2d128b2e-349f-412c-acfa-46e06e78cd46" xlink:href="https://xbrl.sec.gov/country/2020/country-2020-01-31.xsd#country_CA"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NorthAmericaMember_0d5f83e4-cba3-4d93-8a29-c941016f4edb" xlink:to="loc_country_CA_2d128b2e-349f-412c-acfa-46e06e78cd46" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_MX_3f01522e-aaca-4f5f-9e21-b1c871318fce" xlink:href="https://xbrl.sec.gov/country/2020/country-2020-01-31.xsd#country_MX"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NorthAmericaMember_0d5f83e4-cba3-4d93-8a29-c941016f4edb" xlink:to="loc_country_MX_3f01522e-aaca-4f5f-9e21-b1c871318fce" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SouthAmericaMember_5a99a264-8379-4e06-bc58-fa7b75e1538e" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_SouthAmericaMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_8fcec98f-63ac-4aa7-9619-6baed9b240c2" xlink:to="loc_srt_SouthAmericaMember_5a99a264-8379-4e06-bc58-fa7b75e1538e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EuropeMember_264b6274-e235-46d3-8a2b-de68f99a2c7e" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_EuropeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_8fcec98f-63ac-4aa7-9619-6baed9b240c2" xlink:to="loc_srt_EuropeMember_264b6274-e235-46d3-8a2b-de68f99a2c7e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_GB_5c422770-80ba-425b-a0a0-4fb67338e99b" xlink:href="https://xbrl.sec.gov/country/2020/country-2020-01-31.xsd#country_GB"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EuropeMember_264b6274-e235-46d3-8a2b-de68f99a2c7e" xlink:to="loc_country_GB_5c422770-80ba-425b-a0a0-4fb67338e99b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_DE_7d9b3059-8d0f-44dc-ae32-fcdecd2b599d" xlink:href="https://xbrl.sec.gov/country/2020/country-2020-01-31.xsd#country_DE"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EuropeMember_264b6274-e235-46d3-8a2b-de68f99a2c7e" xlink:to="loc_country_DE_7d9b3059-8d0f-44dc-ae32-fcdecd2b599d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_FR_c14718fc-02d2-4f50-808d-3201a6970415" xlink:href="https://xbrl.sec.gov/country/2020/country-2020-01-31.xsd#country_FR"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EuropeMember_264b6274-e235-46d3-8a2b-de68f99a2c7e" xlink:to="loc_country_FR_c14718fc-02d2-4f50-808d-3201a6970415" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_IT_4623486c-a35b-4f41-a55a-0f3af7b72e23" xlink:href="https://xbrl.sec.gov/country/2020/country-2020-01-31.xsd#country_IT"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EuropeMember_264b6274-e235-46d3-8a2b-de68f99a2c7e" xlink:to="loc_country_IT_4623486c-a35b-4f41-a55a-0f3af7b72e23" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_CH_d82806b9-e786-4839-9d8c-ec2aeb68a893" xlink:href="https://xbrl.sec.gov/country/2020/country-2020-01-31.xsd#country_CH"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EuropeMember_264b6274-e235-46d3-8a2b-de68f99a2c7e" xlink:to="loc_country_CH_d82806b9-e786-4839-9d8c-ec2aeb68a893" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_OtherEuropeMember_f77f6416-6e9b-4acb-8b17-41379cd196fe" xlink:href="wab-20201231.xsd#wab_OtherEuropeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EuropeMember_264b6274-e235-46d3-8a2b-de68f99a2c7e" xlink:to="loc_wab_OtherEuropeMember_f77f6416-6e9b-4acb-8b17-41379cd196fe" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_IN_a6f23196-0cfb-4632-8f41-6d3b0c9ef806" xlink:href="https://xbrl.sec.gov/country/2020/country-2020-01-31.xsd#country_IN"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_8fcec98f-63ac-4aa7-9619-6baed9b240c2" xlink:to="loc_country_IN_a6f23196-0cfb-4632-8f41-6d3b0c9ef806" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_AustraliaAndNewZealandMember_c55cfbaf-0ba6-42d1-b49e-5b06f45202ae" xlink:href="wab-20201231.xsd#wab_AustraliaAndNewZealandMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_8fcec98f-63ac-4aa7-9619-6baed9b240c2" xlink:to="loc_wab_AustraliaAndNewZealandMember_c55cfbaf-0ba6-42d1-b49e-5b06f45202ae" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_CN_2f8d744e-3e2e-4f1c-adc0-17d700fa21da" xlink:href="https://xbrl.sec.gov/country/2020/country-2020-01-31.xsd#country_CN"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_8fcec98f-63ac-4aa7-9619-6baed9b240c2" xlink:to="loc_country_CN_2f8d744e-3e2e-4f1c-adc0-17d700fa21da" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_OtherAsiaAndMiddleEastMember_d36c3b01-30d9-444a-acc6-8962375aedc5" xlink:href="wab-20201231.xsd#wab_OtherAsiaAndMiddleEastMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_8fcec98f-63ac-4aa7-9619-6baed9b240c2" xlink:to="loc_wab_OtherAsiaAndMiddleEastMember_d36c3b01-30d9-444a-acc6-8962375aedc5" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_EG_c82a76f5-b54e-4e9f-9e9c-4ed3c8c5273b" xlink:href="https://xbrl.sec.gov/country/2020/country-2020-01-31.xsd#country_EG"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_8fcec98f-63ac-4aa7-9619-6baed9b240c2" xlink:to="loc_country_EG_c82a76f5-b54e-4e9f-9e9c-4ed3c8c5273b" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_OtherAfricaMember_1c964a0d-cf00-44bb-81d1-755afc05fa35" xlink:href="wab-20201231.xsd#wab_OtherAfricaMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_8fcec98f-63ac-4aa7-9619-6baed9b240c2" xlink:to="loc_wab_OtherAfricaMember_1c964a0d-cf00-44bb-81d1-755afc05fa35" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_RussiaAndCISMember_3302f668-b1db-4cc4-88ba-0b7500fdc3b7" xlink:href="wab-20201231.xsd#wab_RussiaAndCISMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_8fcec98f-63ac-4aa7-9619-6baed9b240c2" xlink:to="loc_wab_RussiaAndCISMember_3302f668-b1db-4cc4-88ba-0b7500fdc3b7" xlink:type="arc" order="9"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/SEGMENTINFORMATIONSalesbyProductDetails" xlink:type="simple" xlink:href="wab-20201231.xsd#SEGMENTINFORMATIONSalesbyProductDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/SEGMENTINFORMATIONSalesbyProductDetails" xlink:type="extended" id="i09d5317d2c3045e9990fca0ee3dcd21b_SEGMENTINFORMATIONSalesbyProductDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EntityWideInformationRevenueFromExternalCustomerLineItems_16a914f3-d920-4863-b08d-7b6993303482" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EntityWideInformationRevenueFromExternalCustomerLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_25fd55e9-934a-4f8b-94f2-98005be68ac8" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EntityWideInformationRevenueFromExternalCustomerLineItems_16a914f3-d920-4863-b08d-7b6993303482" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_25fd55e9-934a-4f8b-94f2-98005be68ac8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEntityWideInformationRevenueFromExternalCustomersByProductsAndServicesTable_6bf8dcff-a6b1-429f-8a83-28e7935b051c" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ScheduleOfEntityWideInformationRevenueFromExternalCustomersByProductsAndServicesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_EntityWideInformationRevenueFromExternalCustomerLineItems_16a914f3-d920-4863-b08d-7b6993303482" xlink:to="loc_us-gaap_ScheduleOfEntityWideInformationRevenueFromExternalCustomersByProductsAndServicesTable_6bf8dcff-a6b1-429f-8a83-28e7935b051c" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_b0743264-4223-4e3e-a6d1-ce1cdaeeb5c2" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEntityWideInformationRevenueFromExternalCustomersByProductsAndServicesTable_6bf8dcff-a6b1-429f-8a83-28e7935b051c" xlink:to="loc_srt_ProductOrServiceAxis_b0743264-4223-4e3e-a6d1-ce1cdaeeb5c2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_b0743264-4223-4e3e-a6d1-ce1cdaeeb5c2_default" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_b0743264-4223-4e3e-a6d1-ce1cdaeeb5c2" xlink:to="loc_srt_ProductsAndServicesDomain_b0743264-4223-4e3e-a6d1-ce1cdaeeb5c2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_d26b7e16-2cfa-421c-a171-73ca20dc6c37" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_b0743264-4223-4e3e-a6d1-ce1cdaeeb5c2" xlink:to="loc_srt_ProductsAndServicesDomain_d26b7e16-2cfa-421c-a171-73ca20dc6c37" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquipmentMember_f7ea4215-0d18-4a7f-87ca-89a2d982714c" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_EquipmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_d26b7e16-2cfa-421c-a171-73ca20dc6c37" xlink:to="loc_us-gaap_EquipmentMember_f7ea4215-0d18-4a7f-87ca-89a2d982714c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_ComponentsMember_a1682721-dd3d-47d7-a88d-4ae55e69ae97" xlink:href="wab-20201231.xsd#wab_ComponentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_d26b7e16-2cfa-421c-a171-73ca20dc6c37" xlink:to="loc_wab_ComponentsMember_a1682721-dd3d-47d7-a88d-4ae55e69ae97" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_DigitalElectronicsMember_f79c4ed2-2919-4fd3-885c-da424f7dae66" xlink:href="wab-20201231.xsd#wab_DigitalElectronicsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_d26b7e16-2cfa-421c-a171-73ca20dc6c37" xlink:to="loc_wab_DigitalElectronicsMember_f79c4ed2-2919-4fd3-885c-da424f7dae66" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ServiceMember_95febab2-f6aa-4627-b777-782e0be12672" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ServiceMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_d26b7e16-2cfa-421c-a171-73ca20dc6c37" xlink:to="loc_us-gaap_ServiceMember_95febab2-f6aa-4627-b777-782e0be12672" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_OEMMember_945279df-76a9-4045-9db6-9d2d3f6b82f5" xlink:href="wab-20201231.xsd#wab_OEMMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_d26b7e16-2cfa-421c-a171-73ca20dc6c37" xlink:to="loc_wab_OEMMember_945279df-76a9-4045-9db6-9d2d3f6b82f5" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_AftermarketMember_0f42627a-a08c-4fea-b5f4-a62978cb0354" xlink:href="wab-20201231.xsd#wab_AftermarketMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_d26b7e16-2cfa-421c-a171-73ca20dc6c37" xlink:to="loc_wab_AftermarketMember_0f42627a-a08c-4fea-b5f4-a62978cb0354" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_9259d33b-4ccd-4b1d-b40d-3f9a7293b042" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEntityWideInformationRevenueFromExternalCustomersByProductsAndServicesTable_6bf8dcff-a6b1-429f-8a83-28e7935b051c" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_9259d33b-4ccd-4b1d-b40d-3f9a7293b042" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_9259d33b-4ccd-4b1d-b40d-3f9a7293b042_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_9259d33b-4ccd-4b1d-b40d-3f9a7293b042" xlink:to="loc_us-gaap_SegmentDomain_9259d33b-4ccd-4b1d-b40d-3f9a7293b042_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_3cb3e5ed-ae1d-499c-82c6-5ab75c7d6eac" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_9259d33b-4ccd-4b1d-b40d-3f9a7293b042" xlink:to="loc_us-gaap_SegmentDomain_3cb3e5ed-ae1d-499c-82c6-5ab75c7d6eac" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_FreightSegmentMember_812e3da6-0be9-425a-8fa3-9bf40e54c6f3" xlink:href="wab-20201231.xsd#wab_FreightSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_3cb3e5ed-ae1d-499c-82c6-5ab75c7d6eac" xlink:to="loc_wab_FreightSegmentMember_812e3da6-0be9-425a-8fa3-9bf40e54c6f3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_TransitSegmentMember_5e54b269-4d9d-41c1-a8f4-f3e6423b0cd2" xlink:href="wab-20201231.xsd#wab_TransitSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_3cb3e5ed-ae1d-499c-82c6-5ab75c7d6eac" xlink:to="loc_wab_TransitSegmentMember_5e54b269-4d9d-41c1-a8f4-f3e6423b0cd2" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/OTHERINCOMENET" xlink:type="simple" xlink:href="wab-20201231.xsd#OTHERINCOMENET"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/OTHERINCOMENET" xlink:type="extended" id="i8dc6b58841184eb391971bd7f7d162b9_OTHERINCOMENET"/>
  <link:roleRef roleURI="http://wabtec.com/role/OTHERINCOMENETTables" xlink:type="simple" xlink:href="wab-20201231.xsd#OTHERINCOMENETTables"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/OTHERINCOMENETTables" xlink:type="extended" id="i5de298e4dcd24382a91d05a74e6df3df_OTHERINCOMENETTables"/>
  <link:roleRef roleURI="http://wabtec.com/role/OTHERINCOMENETComponentsofOtherExpenseIncomeDetails" xlink:type="simple" xlink:href="wab-20201231.xsd#OTHERINCOMENETComponentsofOtherExpenseIncomeDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/OTHERINCOMENETComponentsofOtherExpenseIncomeDetails" xlink:type="extended" id="i214eb02dba0b48e48d9f7fe81df615bc_OTHERINCOMENETComponentsofOtherExpenseIncomeDetails"/>
  <link:roleRef roleURI="http://wabtec.com/role/ScheduleIIValuationAndQualifyingAccounts" xlink:type="simple" xlink:href="wab-20201231.xsd#ScheduleIIValuationAndQualifyingAccounts"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/ScheduleIIValuationAndQualifyingAccounts" xlink:type="extended" id="ic34ef05879f14a6daae99a7d24df90db_ScheduleIIValuationAndQualifyingAccounts"/>
  <link:roleRef roleURI="http://wabtec.com/role/ScheduleIIValuationandQualifyingAccountsDetails" xlink:type="simple" xlink:href="wab-20201231.xsd#ScheduleIIValuationandQualifyingAccountsDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/ScheduleIIValuationandQualifyingAccountsDetails" xlink:type="extended" id="i51f94ca3a50c414e9a23fd1e1031278e_ScheduleIIValuationandQualifyingAccountsDetails">
    <link:loc xlink:type="locator" xlink:label="loc_srt_ValuationAndQualifyingAccountsDisclosureLineItems_6af60bea-62a6-451b-b05d-2211a59aba32" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ValuationAndQualifyingAccountsDisclosureLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MovementInValuationAllowancesAndReservesRollForward_ff921fcf-26a4-47a9-9a59-4066183513b0" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_MovementInValuationAllowancesAndReservesRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ValuationAndQualifyingAccountsDisclosureLineItems_6af60bea-62a6-451b-b05d-2211a59aba32" xlink:to="loc_us-gaap_MovementInValuationAllowancesAndReservesRollForward_ff921fcf-26a4-47a9-9a59-4066183513b0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesBalance_650192e6-5fe8-40f3-8bdd-80569fa0e9b3" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ValuationAllowancesAndReservesBalance"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MovementInValuationAllowancesAndReservesRollForward_ff921fcf-26a4-47a9-9a59-4066183513b0" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesBalance_650192e6-5fe8-40f3-8bdd-80569fa0e9b3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense_676a3a4c-20bb-4e89-90ef-f15fa3da95e3" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MovementInValuationAllowancesAndReservesRollForward_ff921fcf-26a4-47a9-9a59-4066183513b0" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense_676a3a4c-20bb-4e89-90ef-f15fa3da95e3" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesChargedToOtherAccounts_2380159f-e257-4eb7-810b-4b92867d9b07" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ValuationAllowancesAndReservesChargedToOtherAccounts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MovementInValuationAllowancesAndReservesRollForward_ff921fcf-26a4-47a9-9a59-4066183513b0" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesChargedToOtherAccounts_2380159f-e257-4eb7-810b-4b92867d9b07" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesDeductions_6c48709a-0c2e-40df-bba3-672d61e07b24" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ValuationAllowancesAndReservesDeductions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MovementInValuationAllowancesAndReservesRollForward_ff921fcf-26a4-47a9-9a59-4066183513b0" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesDeductions_6c48709a-0c2e-40df-bba3-672d61e07b24" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesBalance_adf0027d-c8e6-4bd0-9a56-25328e793c9a" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ValuationAllowancesAndReservesBalance"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ValuationAndQualifyingAccountsDisclosureTable_ca212569-a37f-4d5f-ab7e-5bd4abc1f1cf" xlink:href="http://xbrl.fasb.org/srt/2020/elts/srt-2020-01-31.xsd#srt_ValuationAndQualifyingAccountsDisclosureTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_srt_ValuationAndQualifyingAccountsDisclosureLineItems_6af60bea-62a6-451b-b05d-2211a59aba32" xlink:to="loc_srt_ValuationAndQualifyingAccountsDisclosureTable_ca212569-a37f-4d5f-ab7e-5bd4abc1f1cf" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesTypeAxis_884b7d2d-b349-463a-8d76-5a1624a24845" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ValuationAllowancesAndReservesTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_srt_ValuationAndQualifyingAccountsDisclosureTable_ca212569-a37f-4d5f-ab7e-5bd4abc1f1cf" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesTypeAxis_884b7d2d-b349-463a-8d76-5a1624a24845" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesDomain_884b7d2d-b349-463a-8d76-5a1624a24845_default" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ValuationAllowancesAndReservesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ValuationAllowancesAndReservesTypeAxis_884b7d2d-b349-463a-8d76-5a1624a24845" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesDomain_884b7d2d-b349-463a-8d76-5a1624a24845_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesDomain_412b04f0-bd4a-415e-a55f-1f78e26d4468" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ValuationAllowancesAndReservesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ValuationAllowancesAndReservesTypeAxis_884b7d2d-b349-463a-8d76-5a1624a24845" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesDomain_412b04f0-bd4a-415e-a55f-1f78e26d4468" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllowanceForCreditLossMember_5c08253d-fdab-44b0-a1ba-a9fe7425c3cf" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_AllowanceForCreditLossMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ValuationAllowancesAndReservesDomain_412b04f0-bd4a-415e-a55f-1f78e26d4468" xlink:to="loc_us-gaap_AllowanceForCreditLossMember_5c08253d-fdab-44b0-a1ba-a9fe7425c3cf" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationAllowanceTaxCreditCarryforwardMember_ea50cc68-6a37-4036-a2eb-18496f55a493" xlink:href="http://xbrl.fasb.org/us-gaap/2020/elts/us-gaap-2020-01-31.xsd#us-gaap_ValuationAllowanceTaxCreditCarryforwardMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ValuationAllowancesAndReservesDomain_412b04f0-bd4a-415e-a55f-1f78e26d4468" xlink:to="loc_us-gaap_ValuationAllowanceTaxCreditCarryforwardMember_ea50cc68-6a37-4036-a2eb-18496f55a493" xlink:type="arc" order="1"/>
  </link:definitionLink>
</link:linkbase>
