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

<!--XBRL Document Created with Wdesk from Workiva-->
<!--Copyright 2022 Workiva-->
<!--r:75428693-6d57-46db-9101-ff73d9b6240d,g:bbff24b0-29fc-4697-82ef-18fa97e99f4d-->
<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/CONSOLIDATEDSTATEMENTSOFINCOME" xlink:type="simple" xlink:href="wab-20211231.xsd#CONSOLIDATEDSTATEMENTSOFINCOME"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/CONSOLIDATEDSTATEMENTSOFINCOME" xlink:type="extended" id="if6429abedafa4a53a7b03d30cab5f215_CONSOLIDATEDSTATEMENTSOFINCOME">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_90fcce53-3bdf-4ca6-bfb3-be341277e1a7" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenuesAbstract_0ab68220-4246-4584-8aab-91c6a824767d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RevenuesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_90fcce53-3bdf-4ca6-bfb3-be341277e1a7" xlink:to="loc_us-gaap_RevenuesAbstract_0ab68220-4246-4584-8aab-91c6a824767d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_72bfa3e5-a797-4382-a523-80f444ddfc6e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesAbstract_0ab68220-4246-4584-8aab-91c6a824767d" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_72bfa3e5-a797-4382-a523-80f444ddfc6e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfRevenueAbstract_2ab37ce7-9809-4075-88cd-bce834016120" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CostOfRevenueAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_90fcce53-3bdf-4ca6-bfb3-be341277e1a7" xlink:to="loc_us-gaap_CostOfRevenueAbstract_2ab37ce7-9809-4075-88cd-bce834016120" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfGoodsAndServicesSold_48a696ea-681a-4dad-858b-aab8a248cf9c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CostOfGoodsAndServicesSold"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CostOfRevenueAbstract_2ab37ce7-9809-4075-88cd-bce834016120" xlink:to="loc_us-gaap_CostOfGoodsAndServicesSold_48a696ea-681a-4dad-858b-aab8a248cf9c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GrossProfit_513097f9-8899-441c-a6cd-b11bee9b88b4" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_GrossProfit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_90fcce53-3bdf-4ca6-bfb3-be341277e1a7" xlink:to="loc_us-gaap_GrossProfit_513097f9-8899-441c-a6cd-b11bee9b88b4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingExpensesAbstract_37cfd231-0e63-49ae-ab18-b3b58884ddd8" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OperatingExpensesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_90fcce53-3bdf-4ca6-bfb3-be341277e1a7" xlink:to="loc_us-gaap_OperatingExpensesAbstract_37cfd231-0e63-49ae-ab18-b3b58884ddd8" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SellingGeneralAndAdministrativeExpense_b3db54db-e608-441f-8504-785ad3353ea5" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SellingGeneralAndAdministrativeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_37cfd231-0e63-49ae-ab18-b3b58884ddd8" xlink:to="loc_us-gaap_SellingGeneralAndAdministrativeExpense_b3db54db-e608-441f-8504-785ad3353ea5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ResearchAndDevelopmentExpense_cfc91f9f-f1e6-4468-826b-b14228f21528" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ResearchAndDevelopmentExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_37cfd231-0e63-49ae-ab18-b3b58884ddd8" xlink:to="loc_us-gaap_ResearchAndDevelopmentExpense_cfc91f9f-f1e6-4468-826b-b14228f21528" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfIntangibleAssets_5560f584-5b4d-4b07-8ade-660c4740483e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AmortizationOfIntangibleAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_37cfd231-0e63-49ae-ab18-b3b58884ddd8" xlink:to="loc_us-gaap_AmortizationOfIntangibleAssets_5560f584-5b4d-4b07-8ade-660c4740483e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingExpenses_bcc607e3-c088-4726-b108-35dcb8a452ce" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OperatingExpenses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_37cfd231-0e63-49ae-ab18-b3b58884ddd8" xlink:to="loc_us-gaap_OperatingExpenses_bcc607e3-c088-4726-b108-35dcb8a452ce" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingIncomeLoss_0ce0ec48-ea8a-48de-8ea4-16cce248ca10" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OperatingIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_90fcce53-3bdf-4ca6-bfb3-be341277e1a7" xlink:to="loc_us-gaap_OperatingIncomeLoss_0ce0ec48-ea8a-48de-8ea4-16cce248ca10" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonoperatingIncomeExpenseAbstract_8e20784c-b39f-4424-a3ce-b74f03944fce" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NonoperatingIncomeExpenseAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_90fcce53-3bdf-4ca6-bfb3-be341277e1a7" xlink:to="loc_us-gaap_NonoperatingIncomeExpenseAbstract_8e20784c-b39f-4424-a3ce-b74f03944fce" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeExpenseNet_b4b5c8b6-68f8-434b-83e7-c135eb857cf2" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InterestIncomeExpenseNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NonoperatingIncomeExpenseAbstract_8e20784c-b39f-4424-a3ce-b74f03944fce" xlink:to="loc_us-gaap_InterestIncomeExpenseNet_b4b5c8b6-68f8-434b-83e7-c135eb857cf2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonoperatingIncomeExpense_923fad9f-6e67-4f36-beca-50aa68e8f09b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NonoperatingIncomeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_NonoperatingIncomeExpenseAbstract_8e20784c-b39f-4424-a3ce-b74f03944fce" xlink:to="loc_us-gaap_NonoperatingIncomeExpense_923fad9f-6e67-4f36-beca-50aa68e8f09b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_75c7e889-69bf-49c1-b737-29b6b65a5c83" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_90fcce53-3bdf-4ca6-bfb3-be341277e1a7" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_75c7e889-69bf-49c1-b737-29b6b65a5c83" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_18702ae4-f2b2-4d21-87d4-4f41b4307622" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeTaxExpenseBenefit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_90fcce53-3bdf-4ca6-bfb3-be341277e1a7" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_18702ae4-f2b2-4d21-87d4-4f41b4307622" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfitLoss_26f73a7e-6c5e-44ea-860a-d792df70af1d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProfitLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_90fcce53-3bdf-4ca6-bfb3-be341277e1a7" xlink:to="loc_us-gaap_ProfitLoss_26f73a7e-6c5e-44ea-860a-d792df70af1d" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_075345ae-60aa-43e1-8850-c2c114e5a6a8" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NetIncomeLossAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_90fcce53-3bdf-4ca6-bfb3-be341277e1a7" xlink:to="loc_us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_075345ae-60aa-43e1-8850-c2c114e5a6a8" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_6734cdc1-1337-42fb-81b7-aef44a11ba65" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_90fcce53-3bdf-4ca6-bfb3-be341277e1a7" xlink:to="loc_us-gaap_NetIncomeLoss_6734cdc1-1337-42fb-81b7-aef44a11ba65" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareAbstract_c4937a9f-f45d-457f-a6fd-267531d91471" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EarningsPerShareAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_90fcce53-3bdf-4ca6-bfb3-be341277e1a7" xlink:to="loc_us-gaap_EarningsPerShareAbstract_c4937a9f-f45d-457f-a6fd-267531d91471" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareBasicAbstract_eaed7e03-a577-4337-8905-4f392a4fecf7" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EarningsPerShareBasicAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareAbstract_c4937a9f-f45d-457f-a6fd-267531d91471" xlink:to="loc_us-gaap_EarningsPerShareBasicAbstract_eaed7e03-a577-4337-8905-4f392a4fecf7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareBasic_45e34dbb-7025-4a6d-8b5f-306198080dfe" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EarningsPerShareBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareBasicAbstract_eaed7e03-a577-4337-8905-4f392a4fecf7" xlink:to="loc_us-gaap_EarningsPerShareBasic_45e34dbb-7025-4a6d-8b5f-306198080dfe" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareDilutedAbstract_7558676c-db17-415e-89e9-8f25a1cdcfcd" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EarningsPerShareDilutedAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareAbstract_c4937a9f-f45d-457f-a6fd-267531d91471" xlink:to="loc_us-gaap_EarningsPerShareDilutedAbstract_7558676c-db17-415e-89e9-8f25a1cdcfcd" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareDiluted_e6a4e2bb-f219-4fb0-8021-b8a49b76b80f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EarningsPerShareDiluted"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareDilutedAbstract_7558676c-db17-415e-89e9-8f25a1cdcfcd" xlink:to="loc_us-gaap_EarningsPerShareDiluted_e6a4e2bb-f219-4fb0-8021-b8a49b76b80f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_3589aa0c-2b4b-48e0-83c0-5572a3e0fd67" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_90fcce53-3bdf-4ca6-bfb3-be341277e1a7" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_3589aa0c-2b4b-48e0-83c0-5572a3e0fd67" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_c9effbc7-d19e-4b25-a515-c96f7558f113" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_3589aa0c-2b4b-48e0-83c0-5572a3e0fd67" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_c9effbc7-d19e-4b25-a515-c96f7558f113" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_a35eb61a-3f4b-4d2e-a054-cc13f049089e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingAbstract_3589aa0c-2b4b-48e0-83c0-5572a3e0fd67" xlink:to="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_a35eb61a-3f4b-4d2e-a054-cc13f049089e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_84d5e53d-b517-4559-ad07-006489f72267" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_90fcce53-3bdf-4ca6-bfb3-be341277e1a7" xlink:to="loc_us-gaap_StatementTable_84d5e53d-b517-4559-ad07-006489f72267" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_52f63114-0feb-452a-85a1-36de4433d1a2" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_84d5e53d-b517-4559-ad07-006489f72267" xlink:to="loc_srt_ProductOrServiceAxis_52f63114-0feb-452a-85a1-36de4433d1a2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_52f63114-0feb-452a-85a1-36de4433d1a2_default" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_52f63114-0feb-452a-85a1-36de4433d1a2" xlink:to="loc_srt_ProductsAndServicesDomain_52f63114-0feb-452a-85a1-36de4433d1a2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_49396581-fa5a-41ea-9036-e617b9fd4076" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_52f63114-0feb-452a-85a1-36de4433d1a2" xlink:to="loc_srt_ProductsAndServicesDomain_49396581-fa5a-41ea-9036-e617b9fd4076" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProductMember_adc8866f-cd3c-4af1-85a8-86930fb30ce8" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProductMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_49396581-fa5a-41ea-9036-e617b9fd4076" xlink:to="loc_us-gaap_ProductMember_adc8866f-cd3c-4af1-85a8-86930fb30ce8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ServiceMember_c69bf293-f434-4d86-a2cd-bfc4548d8097" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ServiceMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_49396581-fa5a-41ea-9036-e617b9fd4076" xlink:to="loc_us-gaap_ServiceMember_c69bf293-f434-4d86-a2cd-bfc4548d8097" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/CONSOLIDATEDSTATEMENTSOFSHAREHOLDERSEQUITY" xlink:type="simple" xlink:href="wab-20211231.xsd#CONSOLIDATEDSTATEMENTSOFSHAREHOLDERSEQUITY"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/CONSOLIDATEDSTATEMENTSOFSHAREHOLDERSEQUITY" xlink:type="extended" id="i8db32d3fe50d4985ae03e70060bc1f5e_CONSOLIDATEDSTATEMENTSOFSHAREHOLDERSEQUITY">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_27f8ab16-35cd-4ac4-b34b-e45a3fb6ab0d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_7facbc52-0c5a-46ee-892a-9e99f8e2d22c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncreaseDecreaseInStockholdersEquityRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_27f8ab16-35cd-4ac4-b34b-e45a3fb6ab0d" xlink:to="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_7facbc52-0c5a-46ee-892a-9e99f8e2d22c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharesIssued_d9207ebf-a866-449b-99fc-e8e9dd5e01e0" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_7facbc52-0c5a-46ee-892a-9e99f8e2d22c" xlink:to="loc_us-gaap_SharesIssued_d9207ebf-a866-449b-99fc-e8e9dd5e01e0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_b728e7da-5eef-4933-a5c0-09f46ccc4107" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_7facbc52-0c5a-46ee-892a-9e99f8e2d22c" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_b728e7da-5eef-4933-a5c0-09f46ccc4107" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DividendsCash_a9e0c3bf-81ea-4ad9-aae3-de230f9f63aa" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DividendsCash"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_7facbc52-0c5a-46ee-892a-9e99f8e2d22c" xlink:to="loc_us-gaap_DividendsCash_a9e0c3bf-81ea-4ad9-aae3-de230f9f63aa" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised_1c0768a9-7f79-4d28-bc3f-6cea8b44af2d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_7facbc52-0c5a-46ee-892a-9e99f8e2d22c" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised_1c0768a9-7f79-4d28-bc3f-6cea8b44af2d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_StockGrantedExercisedAndCancelledForVariousEquityInstruments_413d9cba-437d-4284-aeec-f21a63ae1641" xlink:href="wab-20211231.xsd#wab_StockGrantedExercisedAndCancelledForVariousEquityInstruments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_7facbc52-0c5a-46ee-892a-9e99f8e2d22c" xlink:to="loc_wab_StockGrantedExercisedAndCancelledForVariousEquityInstruments_413d9cba-437d-4284-aeec-f21a63ae1641" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_c4f36c1b-51e5-49ad-a475-e278e946ddc2" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_7facbc52-0c5a-46ee-892a-9e99f8e2d22c" xlink:to="loc_us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_c4f36c1b-51e5-49ad-a475-e278e946ddc2" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfitLoss_9ab9aa23-25cf-4393-9ad3-9f2783f116b2" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProfitLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_7facbc52-0c5a-46ee-892a-9e99f8e2d22c" xlink:to="loc_us-gaap_ProfitLoss_9ab9aa23-25cf-4393-9ad3-9f2783f116b2" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_d9c16ecb-33f7-43cf-af0a-ed7a6f98ee06" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_7facbc52-0c5a-46ee-892a-9e99f8e2d22c" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_d9c16ecb-33f7-43cf-af0a-ed7a6f98ee06" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesAcquisitions_78e18957-ff1d-477b-a7b7-6bfb500f3b54" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesAcquisitions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_7facbc52-0c5a-46ee-892a-9e99f8e2d22c" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesAcquisitions_78e18957-ff1d-477b-a7b7-6bfb500f3b54" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueAcquisitions_e91b09c3-d1e0-44e4-9922-123a439687ca" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueAcquisitions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_7facbc52-0c5a-46ee-892a-9e99f8e2d22c" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueAcquisitions_e91b09c3-d1e0-44e4-9922-123a439687ca" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockSharesAcquired_d80caef5-2943-406a-afa8-12db963b7222" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TreasuryStockSharesAcquired"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_7facbc52-0c5a-46ee-892a-9e99f8e2d22c" xlink:to="loc_us-gaap_TreasuryStockSharesAcquired_d80caef5-2943-406a-afa8-12db963b7222" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockValueAcquiredCostMethod_9f55b2d8-a701-4cba-b4d9-5a7c7bd8bbce" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TreasuryStockValueAcquiredCostMethod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_7facbc52-0c5a-46ee-892a-9e99f8e2d22c" xlink:to="loc_us-gaap_TreasuryStockValueAcquiredCostMethod_9f55b2d8-a701-4cba-b4d9-5a7c7bd8bbce" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityOther_19dddb27-dcc7-431e-a648-63ba9e89c2f8" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockholdersEquityOther"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_7facbc52-0c5a-46ee-892a-9e99f8e2d22c" xlink:to="loc_us-gaap_StockholdersEquityOther_19dddb27-dcc7-431e-a648-63ba9e89c2f8" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharesIssued_665ebb04-4c75-4823-8057-8b464294e674" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SharesIssued"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_2708db36-3440-4b84-9923-000b96f70a9e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_da7f67ce-038b-43be-b341-a2f403309c84" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_27f8ab16-35cd-4ac4-b34b-e45a3fb6ab0d" xlink:to="loc_us-gaap_StatementTable_da7f67ce-038b-43be-b341-a2f403309c84" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_88086f36-a652-4a47-89ca-aafa4d82d821" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_da7f67ce-038b-43be-b341-a2f403309c84" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_88086f36-a652-4a47-89ca-aafa4d82d821" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_88086f36-a652-4a47-89ca-aafa4d82d821_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_88086f36-a652-4a47-89ca-aafa4d82d821" xlink:to="loc_us-gaap_EquityComponentDomain_88086f36-a652-4a47-89ca-aafa4d82d821_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_21a3bbd7-c890-480b-a535-3731043737e0" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_88086f36-a652-4a47-89ca-aafa4d82d821" xlink:to="loc_us-gaap_EquityComponentDomain_21a3bbd7-c890-480b-a535-3731043737e0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_e09dab4e-833c-4d16-b2e5-fa9fbd550a4f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_21a3bbd7-c890-480b-a535-3731043737e0" xlink:to="loc_us-gaap_CommonStockMember_e09dab4e-833c-4d16-b2e5-fa9fbd550a4f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalMember_9ef7ac15-4054-4c5b-a937-52384c5982de" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AdditionalPaidInCapitalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_21a3bbd7-c890-480b-a535-3731043737e0" xlink:to="loc_us-gaap_AdditionalPaidInCapitalMember_9ef7ac15-4054-4c5b-a937-52384c5982de" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockMember_c61d9b20-6cff-4aa6-9020-db74e80059e0" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TreasuryStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_21a3bbd7-c890-480b-a535-3731043737e0" xlink:to="loc_us-gaap_TreasuryStockMember_c61d9b20-6cff-4aa6-9020-db74e80059e0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsMember_0aa59faf-f6e6-4ef4-a653-11378225993c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetainedEarningsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_21a3bbd7-c890-480b-a535-3731043737e0" xlink:to="loc_us-gaap_RetainedEarningsMember_0aa59faf-f6e6-4ef4-a653-11378225993c" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_7bc9577d-b9a9-4471-9ecc-3bd930f85093" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_21a3bbd7-c890-480b-a535-3731043737e0" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_7bc9577d-b9a9-4471-9ecc-3bd930f85093" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NoncontrollingInterestMember_73b0030d-b990-43ab-8192-de0587d50f6c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NoncontrollingInterestMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_21a3bbd7-c890-480b-a535-3731043737e0" xlink:to="loc_us-gaap_NoncontrollingInterestMember_73b0030d-b990-43ab-8192-de0587d50f6c" xlink:type="arc" order="5"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/BUSINESSNarrativeDetails" xlink:type="simple" xlink:href="wab-20211231.xsd#BUSINESSNarrativeDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/BUSINESSNarrativeDetails" xlink:type="extended" id="iff2dbc3145014fb394dfab41cb2d7dfb_BUSINESSNarrativeDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProductInformationLineItems_e016c9ad-b878-4a6e-9b10-2d216fd716f1" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProductInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NumberOfCountriesInWhichEntityOperates_9bc3d7c7-62ad-4308-b8bd-83afaee1d045" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NumberOfCountriesInWhichEntityOperates"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ProductInformationLineItems_e016c9ad-b878-4a6e-9b10-2d216fd716f1" xlink:to="loc_us-gaap_NumberOfCountriesInWhichEntityOperates_9bc3d7c7-62ad-4308-b8bd-83afaee1d045" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_NumberOfCountriesWhereProductFound_b458d5a6-6336-40d2-bb9f-dc53b74c3ebf" xlink:href="wab-20211231.xsd#wab_NumberOfCountriesWhereProductFound"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ProductInformationLineItems_e016c9ad-b878-4a6e-9b10-2d216fd716f1" xlink:to="loc_wab_NumberOfCountriesWhereProductFound_b458d5a6-6336-40d2-bb9f-dc53b74c3ebf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskPercentage1_c6317eff-e01e-40af-bd8e-dd3a36492dc9" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ConcentrationRiskPercentage1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ProductInformationLineItems_e016c9ad-b878-4a6e-9b10-2d216fd716f1" xlink:to="loc_us-gaap_ConcentrationRiskPercentage1_c6317eff-e01e-40af-bd8e-dd3a36492dc9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfProductInformationTable_df93d408-ac79-4124-9b4d-f6126fd38770" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfProductInformationTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ProductInformationLineItems_e016c9ad-b878-4a6e-9b10-2d216fd716f1" xlink:to="loc_us-gaap_ScheduleOfProductInformationTable_df93d408-ac79-4124-9b4d-f6126fd38770" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_0df51f07-1a43-40f4-9c90-5411a5817072" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ConcentrationRiskByBenchmarkAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfProductInformationTable_df93d408-ac79-4124-9b4d-f6126fd38770" xlink:to="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_0df51f07-1a43-40f4-9c90-5411a5817072" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_0df51f07-1a43-40f4-9c90-5411a5817072_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_0df51f07-1a43-40f4-9c90-5411a5817072" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_0df51f07-1a43-40f4-9c90-5411a5817072_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_e5aa5810-a9ea-456f-bdae-fdd8eb4599a1" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_0df51f07-1a43-40f4-9c90-5411a5817072" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_e5aa5810-a9ea-456f-bdae-fdd8eb4599a1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerMember_93be74ed-9b42-41b9-946d-f2d837673d47" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RevenueFromContractWithCustomerMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskBenchmarkDomain_e5aa5810-a9ea-456f-bdae-fdd8eb4599a1" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerMember_93be74ed-9b42-41b9-946d-f2d837673d47" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByTypeAxis_3afdd636-e19e-47f1-9439-13fe0eb66fef" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ConcentrationRiskByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfProductInformationTable_df93d408-ac79-4124-9b4d-f6126fd38770" xlink:to="loc_us-gaap_ConcentrationRiskByTypeAxis_3afdd636-e19e-47f1-9439-13fe0eb66fef" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_3afdd636-e19e-47f1-9439-13fe0eb66fef_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_3afdd636-e19e-47f1-9439-13fe0eb66fef" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_3afdd636-e19e-47f1-9439-13fe0eb66fef_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_13d12611-d311-4241-9e56-aeef17f7b810" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_3afdd636-e19e-47f1-9439-13fe0eb66fef" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_13d12611-d311-4241-9e56-aeef17f7b810" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GeographicConcentrationRiskMember_9e888503-9e31-4309-a34f-c54625aad71b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_GeographicConcentrationRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskTypeDomain_13d12611-d311-4241-9e56-aeef17f7b810" xlink:to="loc_us-gaap_GeographicConcentrationRiskMember_9e888503-9e31-4309-a34f-c54625aad71b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis_c887ae31-6eda-40dc-a996-d81c92464ad3" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_StatementGeographicalAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfProductInformationTable_df93d408-ac79-4124-9b4d-f6126fd38770" xlink:to="loc_srt_StatementGeographicalAxis_c887ae31-6eda-40dc-a996-d81c92464ad3" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_c887ae31-6eda-40dc-a996-d81c92464ad3_default" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_c887ae31-6eda-40dc-a996-d81c92464ad3" xlink:to="loc_srt_SegmentGeographicalDomain_c887ae31-6eda-40dc-a996-d81c92464ad3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_47fe82ea-1ed3-4b4d-966c-bca268ab21bf" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_c887ae31-6eda-40dc-a996-d81c92464ad3" xlink:to="loc_srt_SegmentGeographicalDomain_47fe82ea-1ed3-4b4d-966c-bca268ab21bf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NonUsMember_cfa348e9-5803-4b0b-be14-ba71fcd599c0" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NonUsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_47fe82ea-1ed3-4b4d-966c-bca268ab21bf" xlink:to="loc_us-gaap_NonUsMember_cfa348e9-5803-4b0b-be14-ba71fcd599c0" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails" xlink:type="simple" xlink:href="wab-20211231.xsd#SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails" xlink:type="extended" id="i7c24154c7e324696a9066a70085538f6_SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESNarrativeDetails">
    <link:loc xlink:type="locator" xlink:label="loc_wab_SummaryOfSignificantAccountingPoliciesLineItems_b5e918a7-1817-4191-9db3-91bd859e4cde" xlink:href="wab-20211231.xsd#wab_SummaryOfSignificantAccountingPoliciesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProvisionForDoubtfulAccounts_38210f22-4e49-400e-a7a6-345ba59772cd" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProvisionForDoubtfulAccounts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_wab_SummaryOfSignificantAccountingPoliciesLineItems_b5e918a7-1817-4191-9db3-91bd859e4cde" xlink:to="loc_us-gaap_ProvisionForDoubtfulAccounts_38210f22-4e49-400e-a7a6-345ba59772cd" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityMethodInvestments_62104b84-1803-45ac-bafc-4df9198a9afb" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EquityMethodInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_wab_SummaryOfSignificantAccountingPoliciesLineItems_b5e918a7-1817-4191-9db3-91bd859e4cde" xlink:to="loc_us-gaap_EquityMethodInvestments_62104b84-1803-45ac-bafc-4df9198a9afb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignCurrencyTransactionGainLossRealized_1c439556-9072-4028-a812-ef53667b0703" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ForeignCurrencyTransactionGainLossRealized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_wab_SummaryOfSignificantAccountingPoliciesLineItems_b5e918a7-1817-4191-9db3-91bd859e4cde" xlink:to="loc_us-gaap_ForeignCurrencyTransactionGainLossRealized_1c439556-9072-4028-a812-ef53667b0703" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_AccountsReceivableAfterAllowanceForCreditLossMaximumRecurringTransfer_8ddba1a5-cb46-44e1-baa4-d7a19252d5ec" xlink:href="wab-20211231.xsd#wab_AccountsReceivableAfterAllowanceForCreditLossMaximumRecurringTransfer"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_wab_SummaryOfSignificantAccountingPoliciesLineItems_b5e918a7-1817-4191-9db3-91bd859e4cde" xlink:to="loc_wab_AccountsReceivableAfterAllowanceForCreditLossMaximumRecurringTransfer_8ddba1a5-cb46-44e1-baa4-d7a19252d5ec" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccountsReceivableNetCurrent_f4b9d1e0-6de2-48b9-ab59-aaeff7023122" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccountsReceivableNetCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_wab_SummaryOfSignificantAccountingPoliciesLineItems_b5e918a7-1817-4191-9db3-91bd859e4cde" xlink:to="loc_us-gaap_AccountsReceivableNetCurrent_f4b9d1e0-6de2-48b9-ab59-aaeff7023122" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreproductionCostsRelatedToLongTermSupplyArrangementsCostsCapitalized_6c430306-53b4-497b-b337-a6b41fd971e8" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PreproductionCostsRelatedToLongTermSupplyArrangementsCostsCapitalized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_wab_SummaryOfSignificantAccountingPoliciesLineItems_b5e918a7-1817-4191-9db3-91bd859e4cde" xlink:to="loc_us-gaap_PreproductionCostsRelatedToLongTermSupplyArrangementsCostsCapitalized_6c430306-53b4-497b-b337-a6b41fd971e8" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesAuthorized_9ff23de9-7b4e-4276-af55-edf500037998" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PreferredStockSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_wab_SummaryOfSignificantAccountingPoliciesLineItems_b5e918a7-1817-4191-9db3-91bd859e4cde" xlink:to="loc_us-gaap_PreferredStockSharesAuthorized_9ff23de9-7b4e-4276-af55-edf500037998" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesIssued_a0d6df75-fc74-4067-88b5-291894d6ddf5" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PreferredStockSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_wab_SummaryOfSignificantAccountingPoliciesLineItems_b5e918a7-1817-4191-9db3-91bd859e4cde" xlink:to="loc_us-gaap_PreferredStockSharesIssued_a0d6df75-fc74-4067-88b5-291894d6ddf5" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesOutstanding_e5cb4b61-4383-47b0-93ab-e658a1638a5a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PreferredStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_wab_SummaryOfSignificantAccountingPoliciesLineItems_b5e918a7-1817-4191-9db3-91bd859e4cde" xlink:to="loc_us-gaap_PreferredStockSharesOutstanding_e5cb4b61-4383-47b0-93ab-e658a1638a5a" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_SummaryOfSignificantAccountingPoliciesTable_e40bcbae-c7ea-4325-871e-f6dfc5b3438a" xlink:href="wab-20211231.xsd#wab_SummaryOfSignificantAccountingPoliciesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_wab_SummaryOfSignificantAccountingPoliciesLineItems_b5e918a7-1817-4191-9db3-91bd859e4cde" xlink:to="loc_wab_SummaryOfSignificantAccountingPoliciesTable_e40bcbae-c7ea-4325-871e-f6dfc5b3438a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CollateralAxis_6c1e3597-325d-4ba2-a9bd-2f578edf059d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CollateralAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_wab_SummaryOfSignificantAccountingPoliciesTable_e40bcbae-c7ea-4325-871e-f6dfc5b3438a" xlink:to="loc_us-gaap_CollateralAxis_6c1e3597-325d-4ba2-a9bd-2f578edf059d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CollateralDomain_6c1e3597-325d-4ba2-a9bd-2f578edf059d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CollateralDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CollateralAxis_6c1e3597-325d-4ba2-a9bd-2f578edf059d" xlink:to="loc_us-gaap_CollateralDomain_6c1e3597-325d-4ba2-a9bd-2f578edf059d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CollateralDomain_cbb9fb93-a542-4337-b26e-0d8b8522cdfd" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CollateralDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CollateralAxis_6c1e3597-325d-4ba2-a9bd-2f578edf059d" xlink:to="loc_us-gaap_CollateralDomain_cbb9fb93-a542-4337-b26e-0d8b8522cdfd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CollateralPledgedMember_8ce14ef2-277f-44ec-acf9-38f93f2aaa1d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CollateralPledgedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CollateralDomain_cbb9fb93-a542-4337-b26e-0d8b8522cdfd" xlink:to="loc_us-gaap_CollateralPledgedMember_8ce14ef2-277f-44ec-acf9-38f93f2aaa1d" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESPerformanceObligationDetails" xlink:type="simple" xlink:href="wab-20211231.xsd#SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESPerformanceObligationDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESPerformanceObligationDetails" xlink:type="extended" id="i519a448aab6f451fb4fc7d42079ef912_SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESPerformanceObligationDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_74468a17-09e5-406d-b970-f9ceda19f258" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligation_3a356f2b-1249-49c5-813a-ebb9ed4c1f9d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_74468a17-09e5-406d-b970-f9ceda19f258" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligation_3a356f2b-1249-49c5-813a-ebb9ed4c1f9d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationPercentage_49c6b7bc-9679-4407-a646-772162cbd493" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligationPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_74468a17-09e5-406d-b970-f9ceda19f258" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationPercentage_49c6b7bc-9679-4407-a646-772162cbd493" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_35a8abb5-fcf6-4611-99d4-769dedb36a5d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_74468a17-09e5-406d-b970-f9ceda19f258" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_35a8abb5-fcf6-4611-99d4-769dedb36a5d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_d54c37ce-eaee-4e52-901f-f3e438380adb" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_74468a17-09e5-406d-b970-f9ceda19f258" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_d54c37ce-eaee-4e52-901f-f3e438380adb" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis_c7c6df34-aa75-4518-8aa4-8ccc7df08a0d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_d54c37ce-eaee-4e52-901f-f3e438380adb" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionStartDateAxis_c7c6df34-aa75-4518-8aa4-8ccc7df08a0d" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESPerformanceObligationDetails_1" xlink:type="simple" xlink:href="wab-20211231.xsd#SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESPerformanceObligationDetails_1"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESPerformanceObligationDetails_1" xlink:type="extended" id="ib7beec770ee0429db993c9105217c5c3_SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESPerformanceObligationDetails_1">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_74468a17-09e5-406d-b970-f9ceda19f258" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligation_3a356f2b-1249-49c5-813a-ebb9ed4c1f9d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_74468a17-09e5-406d-b970-f9ceda19f258" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligation_3a356f2b-1249-49c5-813a-ebb9ed4c1f9d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationPercentage_49c6b7bc-9679-4407-a646-772162cbd493" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligationPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_74468a17-09e5-406d-b970-f9ceda19f258" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationPercentage_49c6b7bc-9679-4407-a646-772162cbd493" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_35a8abb5-fcf6-4611-99d4-769dedb36a5d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_74468a17-09e5-406d-b970-f9ceda19f258" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1_35a8abb5-fcf6-4611-99d4-769dedb36a5d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_d54c37ce-eaee-4e52-901f-f3e438380adb" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionLineItems_74468a17-09e5-406d-b970-f9ceda19f258" xlink:to="loc_us-gaap_RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionTable_d54c37ce-eaee-4e52-901f-f3e438380adb" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/ACQUISITIONSNarrativeDetails" xlink:type="simple" xlink:href="wab-20211231.xsd#ACQUISITIONSNarrativeDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/ACQUISITIONSNarrativeDetails" xlink:type="extended" id="if14bb602c05c475e85ac3d2a517e1161_ACQUISITIONSNarrativeDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_5b8e2ff8-bdbd-42a3-acb3-ac931681301e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessAcquisitionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired_172202f6-f40e-4156-92f3-20a92b5b5518" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5b8e2ff8-bdbd-42a3-acb3-ac931681301e" xlink:to="loc_us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired_172202f6-f40e-4156-92f3-20a92b5b5518" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferred1_e8a0246b-6c9f-471f-9b66-3de62fa10101" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessCombinationConsiderationTransferred1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5b8e2ff8-bdbd-42a3-acb3-ac931681301e" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferred1_e8a0246b-6c9f-471f-9b66-3de62fa10101" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_BusinessCombinationConsiderationTransferredCertainIdentifiableAssetsofAcquired_8a9b3ff1-d9cf-4951-9e00-b97568f67d4d" xlink:href="wab-20211231.xsd#wab_BusinessCombinationConsiderationTransferredCertainIdentifiableAssetsofAcquired"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5b8e2ff8-bdbd-42a3-acb3-ac931681301e" xlink:to="loc_wab_BusinessCombinationConsiderationTransferredCertainIdentifiableAssetsofAcquired_8a9b3ff1-d9cf-4951-9e00-b97568f67d4d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_8de7d208-9b7c-420e-9368-0b2004aba767" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5b8e2ff8-bdbd-42a3-acb3-ac931681301e" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_8de7d208-9b7c-420e-9368-0b2004aba767" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesOutstanding_c3c1699d-ce45-4bd9-9bf4-cfff53473bf7" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PreferredStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5b8e2ff8-bdbd-42a3-acb3-ac931681301e" xlink:to="loc_us-gaap_PreferredStockSharesOutstanding_c3c1699d-ce45-4bd9-9bf4-cfff53473bf7" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued_48f2df06-e20d-41e4-b245-399d05416f9b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5b8e2ff8-bdbd-42a3-acb3-ac931681301e" xlink:to="loc_us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued_48f2df06-e20d-41e4-b245-399d05416f9b" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_BusinessCombinationPercentageofOutstandingSharesTransferred_5a9db7e8-0d84-4a98-b9ef-e7b246bbb1e2" xlink:href="wab-20211231.xsd#wab_BusinessCombinationPercentageofOutstandingSharesTransferred"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5b8e2ff8-bdbd-42a3-acb3-ac931681301e" xlink:to="loc_wab_BusinessCombinationPercentageofOutstandingSharesTransferred_5a9db7e8-0d84-4a98-b9ef-e7b246bbb1e2" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireBusinessesGross_3c729020-e9fb-4ad6-ad1b-47c8f0792149" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PaymentsToAcquireBusinessesGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5b8e2ff8-bdbd-42a3-acb3-ac931681301e" xlink:to="loc_us-gaap_PaymentsToAcquireBusinessesGross_3c729020-e9fb-4ad6-ad1b-47c8f0792149" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesIssued_b5e172e5-bb65-442a-a874-209af86e945a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommonStockSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5b8e2ff8-bdbd-42a3-acb3-ac931681301e" xlink:to="loc_us-gaap_CommonStockSharesIssued_b5e172e5-bb65-442a-a874-209af86e945a" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PreferredStockSharesIssued_444e4ba7-b757-4ba1-9941-16abbd1902b9" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PreferredStockSharesIssued"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5b8e2ff8-bdbd-42a3-acb3-ac931681301e" xlink:to="loc_us-gaap_PreferredStockSharesIssued_444e4ba7-b757-4ba1-9941-16abbd1902b9" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction_1c4d2165-40a7-43cd-833c-0f97c9f9891a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5b8e2ff8-bdbd-42a3-acb3-ac931681301e" xlink:to="loc_us-gaap_SaleOfStockNumberOfSharesIssuedInTransaction_1c4d2165-40a7-43cd-833c-0f97c9f9891a" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionSharePrice_a6099d3f-f67c-4c20-90cd-6f60abc0f3b1" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessAcquisitionSharePrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5b8e2ff8-bdbd-42a3-acb3-ac931681301e" xlink:to="loc_us-gaap_BusinessAcquisitionSharePrice_a6099d3f-f67c-4c20-90cd-6f60abc0f3b1" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationAcquisitionOfLessThan100PercentNoncontrollingInterestFairValue_3250ce0a-9ed9-4768-9cab-860900d1330b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessCombinationAcquisitionOfLessThan100PercentNoncontrollingInterestFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5b8e2ff8-bdbd-42a3-acb3-ac931681301e" xlink:to="loc_us-gaap_BusinessCombinationAcquisitionOfLessThan100PercentNoncontrollingInterestFairValue_3250ce0a-9ed9-4768-9cab-860900d1330b" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther_e7654858-3426-4279-bcb0-45a262589e54" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5b8e2ff8-bdbd-42a3-acb3-ac931681301e" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther_e7654858-3426-4279-bcb0-45a262589e54" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationAsset1_9042ed89-b27f-4afd-a95a-83ae6ac0930b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationAsset1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5b8e2ff8-bdbd-42a3-acb3-ac931681301e" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationAsset1_9042ed89-b27f-4afd-a95a-83ae6ac0930b" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_77c444d2-62fa-43d2-98fa-af4fd74a39fd" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_5b8e2ff8-bdbd-42a3-acb3-ac931681301e" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_77c444d2-62fa-43d2-98fa-af4fd74a39fd" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_6adc4e72-d4cd-4d97-be7d-4e5afe2a3bf8" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_77c444d2-62fa-43d2-98fa-af4fd74a39fd" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_6adc4e72-d4cd-4d97-be7d-4e5afe2a3bf8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_6adc4e72-d4cd-4d97-be7d-4e5afe2a3bf8_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_6adc4e72-d4cd-4d97-be7d-4e5afe2a3bf8" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_6adc4e72-d4cd-4d97-be7d-4e5afe2a3bf8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_fde9f473-765f-4abb-9782-df58f0eec70e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_6adc4e72-d4cd-4d97-be7d-4e5afe2a3bf8" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_fde9f473-765f-4abb-9782-df58f0eec70e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_NordcoMember_84b8c6d7-f53c-4533-9e19-f474e01ed15c" xlink:href="wab-20211231.xsd#wab_NordcoMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_fde9f473-765f-4abb-9782-df58f0eec70e" xlink:to="loc_wab_NordcoMember_84b8c6d7-f53c-4533-9e19-f474e01ed15c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_GETransportationMember_5fc8592a-747b-48d2-abe5-dd82e948cf7d" xlink:href="wab-20211231.xsd#wab_GETransportationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_fde9f473-765f-4abb-9782-df58f0eec70e" xlink:to="loc_wab_GETransportationMember_5fc8592a-747b-48d2-abe5-dd82e948cf7d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_GETBrazilMember_3677afef-965c-4836-a7ec-e34e52506d98" xlink:href="wab-20211231.xsd#wab_GETBrazilMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_fde9f473-765f-4abb-9782-df58f0eec70e" xlink:to="loc_wab_GETBrazilMember_3677afef-965c-4836-a7ec-e34e52506d98" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_GeneralElectricCompanyMember_8e41c7dd-3517-442c-9bdd-64f4c3c8bfa0" xlink:href="wab-20211231.xsd#wab_GeneralElectricCompanyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_fde9f473-765f-4abb-9782-df58f0eec70e" xlink:to="loc_wab_GeneralElectricCompanyMember_8e41c7dd-3517-442c-9bdd-64f4c3c8bfa0" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_2d269f67-c13c-44ff-a1e7-d44bf48a49c2" xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_77c444d2-62fa-43d2-98fa-af4fd74a39fd" xlink:to="loc_dei_LegalEntityAxis_2d269f67-c13c-44ff-a1e7-d44bf48a49c2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_2d269f67-c13c-44ff-a1e7-d44bf48a49c2_default" xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_2d269f67-c13c-44ff-a1e7-d44bf48a49c2" xlink:to="loc_dei_EntityDomain_2d269f67-c13c-44ff-a1e7-d44bf48a49c2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_39a1ea5a-75a0-4e41-8598-fe545404e8d7" xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_2d269f67-c13c-44ff-a1e7-d44bf48a49c2" xlink:to="loc_dei_EntityDomain_39a1ea5a-75a0-4e41-8598-fe545404e8d7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_GeneralElectricCompanyMember_d855243e-f698-4b2d-8350-3939f21c1228" xlink:href="wab-20211231.xsd#wab_GeneralElectricCompanyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_39a1ea5a-75a0-4e41-8598-fe545404e8d7" xlink:to="loc_wab_GeneralElectricCompanyMember_d855243e-f698-4b2d-8350-3939f21c1228" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_PremergerWabtecStockholdersMember_c1cdb960-e5e3-4187-9bce-fc40053a7ccb" xlink:href="wab-20211231.xsd#wab_PremergerWabtecStockholdersMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_39a1ea5a-75a0-4e41-8598-fe545404e8d7" xlink:to="loc_wab_PremergerWabtecStockholdersMember_c1cdb960-e5e3-4187-9bce-fc40053a7ccb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_WabtecMember_3c6be7ae-1874-445b-93ac-a5d479812afd" xlink:href="wab-20211231.xsd#wab_WabtecMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_39a1ea5a-75a0-4e41-8598-fe545404e8d7" xlink:to="loc_wab_WabtecMember_3c6be7ae-1874-445b-93ac-a5d479812afd" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_f86b0c61-5eba-46b4-ac17-60e9c951bfb8" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_77c444d2-62fa-43d2-98fa-af4fd74a39fd" xlink:to="loc_us-gaap_StatementClassOfStockAxis_f86b0c61-5eba-46b4-ac17-60e9c951bfb8" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_f86b0c61-5eba-46b4-ac17-60e9c951bfb8_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_f86b0c61-5eba-46b4-ac17-60e9c951bfb8" xlink:to="loc_us-gaap_ClassOfStockDomain_f86b0c61-5eba-46b4-ac17-60e9c951bfb8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_4f6a7153-f219-4e77-b1ff-9386718f41c9" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_f86b0c61-5eba-46b4-ac17-60e9c951bfb8" xlink:to="loc_us-gaap_ClassOfStockDomain_4f6a7153-f219-4e77-b1ff-9386718f41c9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_SpinCoCommonStockMember_61041181-db67-4678-bf16-165269a8a1d7" xlink:href="wab-20211231.xsd#wab_SpinCoCommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_4f6a7153-f219-4e77-b1ff-9386718f41c9" xlink:to="loc_wab_SpinCoCommonStockMember_61041181-db67-4678-bf16-165269a8a1d7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_SpinCoClassAPreferredStockMember_239bb008-c2d8-4f56-9650-5edee430cc3c" xlink:href="wab-20211231.xsd#wab_SpinCoClassAPreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_4f6a7153-f219-4e77-b1ff-9386718f41c9" xlink:to="loc_wab_SpinCoClassAPreferredStockMember_239bb008-c2d8-4f56-9650-5edee430cc3c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_SpinCoClassBPreferredStockMember_4e9bcfe2-f3fb-4969-816e-6ec3d073223f" xlink:href="wab-20211231.xsd#wab_SpinCoClassBPreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_4f6a7153-f219-4e77-b1ff-9386718f41c9" xlink:to="loc_wab_SpinCoClassBPreferredStockMember_4e9bcfe2-f3fb-4969-816e-6ec3d073223f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_SpinCoClassCPreferredStockMember_d73b8dbc-23e9-41fa-9c18-46526e0ecdeb" xlink:href="wab-20211231.xsd#wab_SpinCoClassCPreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_4f6a7153-f219-4e77-b1ff-9386718f41c9" xlink:to="loc_wab_SpinCoClassCPreferredStockMember_d73b8dbc-23e9-41fa-9c18-46526e0ecdeb" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConvertiblePreferredStockMember_03f99cf0-92c2-4793-93ec-eefd66f158e7" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ConvertiblePreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_4f6a7153-f219-4e77-b1ff-9386718f41c9" xlink:to="loc_us-gaap_ConvertiblePreferredStockMember_03f99cf0-92c2-4793-93ec-eefd66f158e7" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeriesAPreferredStockMember_5604e3f4-471b-4c64-881a-3439e8f26e3d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SeriesAPreferredStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_4f6a7153-f219-4e77-b1ff-9386718f41c9" xlink:to="loc_us-gaap_SeriesAPreferredStockMember_5604e3f4-471b-4c64-881a-3439e8f26e3d" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_9792fd16-c811-4b1c-abbe-82d54fdd2d2e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_4f6a7153-f219-4e77-b1ff-9386718f41c9" xlink:to="loc_us-gaap_CommonStockMember_9792fd16-c811-4b1c-abbe-82d54fdd2d2e" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_OwnershipAxis_49698ff2-7863-4aca-8691-5d037ce29a60" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_OwnershipAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_77c444d2-62fa-43d2-98fa-af4fd74a39fd" xlink:to="loc_srt_OwnershipAxis_49698ff2-7863-4aca-8691-5d037ce29a60" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_OwnershipDomain_49698ff2-7863-4aca-8691-5d037ce29a60_default" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_OwnershipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_OwnershipAxis_49698ff2-7863-4aca-8691-5d037ce29a60" xlink:to="loc_srt_OwnershipDomain_49698ff2-7863-4aca-8691-5d037ce29a60_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_OwnershipDomain_129fc6c8-8f64-45d1-a3ec-19525d5830df" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_OwnershipDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_OwnershipAxis_49698ff2-7863-4aca-8691-5d037ce29a60" xlink:to="loc_srt_OwnershipDomain_129fc6c8-8f64-45d1-a3ec-19525d5830df" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_GeneralElectricCompanyMember_1546deba-6695-42dc-9a59-a2c8f5ff9151" xlink:href="wab-20211231.xsd#wab_GeneralElectricCompanyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_OwnershipDomain_129fc6c8-8f64-45d1-a3ec-19525d5830df" xlink:to="loc_wab_GeneralElectricCompanyMember_1546deba-6695-42dc-9a59-a2c8f5ff9151" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_GEandPreMergerHoldersMember_5b3a4751-4293-4977-a56a-54b8c53abdd0" xlink:href="wab-20211231.xsd#wab_GEandPreMergerHoldersMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_OwnershipDomain_129fc6c8-8f64-45d1-a3ec-19525d5830df" xlink:to="loc_wab_GEandPreMergerHoldersMember_5b3a4751-4293-4977-a56a-54b8c53abdd0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByLiabilityClassAxis_02bd6db4-3e3e-4c08-9e9d-553100c53597" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueByLiabilityClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_77c444d2-62fa-43d2-98fa-af4fd74a39fd" xlink:to="loc_us-gaap_FairValueByLiabilityClassAxis_02bd6db4-3e3e-4c08-9e9d-553100c53597" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_02bd6db4-3e3e-4c08-9e9d-553100c53597_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByLiabilityClassAxis_02bd6db4-3e3e-4c08-9e9d-553100c53597" xlink:to="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_02bd6db4-3e3e-4c08-9e9d-553100c53597_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_9c65e01d-e9e6-4a97-a2f0-cb7deac2c908" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByLiabilityClassAxis_02bd6db4-3e3e-4c08-9e9d-553100c53597" xlink:to="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_9c65e01d-e9e6-4a97-a2f0-cb7deac2c908" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerContractsMember_fac2d578-def7-4694-9cf2-ad776af50cfa" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CustomerContractsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_9c65e01d-e9e6-4a97-a2f0-cb7deac2c908" xlink:to="loc_us-gaap_CustomerContractsMember_fac2d578-def7-4694-9cf2-ad776af50cfa" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/ACQUISITIONSSummaryofFairValueofNordcoAssetsAcquiredandLiabilitiesAssumedDetails" xlink:type="simple" xlink:href="wab-20211231.xsd#ACQUISITIONSSummaryofFairValueofNordcoAssetsAcquiredandLiabilitiesAssumedDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/ACQUISITIONSSummaryofFairValueofNordcoAssetsAcquiredandLiabilitiesAssumedDetails" xlink:type="extended" id="i11229aa53c5f4eaea906d0d4585a9e01_ACQUISITIONSSummaryofFairValueofNordcoAssetsAcquiredandLiabilitiesAssumedDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_cb92234a-c362-450a-b15b-5f3b77a1340e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessAcquisitionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_41dd5298-b56f-4448-a112-49eeafe09a9e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_cb92234a-c362-450a-b15b-5f3b77a1340e" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_41dd5298-b56f-4448-a112-49eeafe09a9e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents_764217f0-3fe1-4d76-ba5a-63dc38d6d9da" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_41dd5298-b56f-4448-a112-49eeafe09a9e" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents_764217f0-3fe1-4d76-ba5a-63dc38d6d9da" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables_9ba63b56-b898-4923-9366-9b18548f0f51" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_41dd5298-b56f-4448-a112-49eeafe09a9e" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables_9ba63b56-b898-4923-9366-9b18548f0f51" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory_b7e6af5a-81da-4961-bafe-bf994d20b0b4" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_41dd5298-b56f-4448-a112-49eeafe09a9e" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory_b7e6af5a-81da-4961-bafe-bf994d20b0b4" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsOther_df59a92c-ac43-4370-bb9c-f0b5d90c7ab0" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsOther"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_41dd5298-b56f-4448-a112-49eeafe09a9e" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsOther_df59a92c-ac43-4370-bb9c-f0b5d90c7ab0" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment_d9986faf-aa05-474c-82b1-de199f9b0b14" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_41dd5298-b56f-4448-a112-49eeafe09a9e" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment_d9986faf-aa05-474c-82b1-de199f9b0b14" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_7acffa19-23fe-41fe-bed2-98f566522243" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_Goodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_41dd5298-b56f-4448-a112-49eeafe09a9e" xlink:to="loc_us-gaap_Goodwill_7acffa19-23fe-41fe-bed2-98f566522243" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill_23bb6169-57ec-4219-bc53-2a805bcc7474" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_41dd5298-b56f-4448-a112-49eeafe09a9e" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibleAssetsOtherThanGoodwill_23bb6169-57ec-4219-bc53-2a805bcc7474" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherNoncurrentAssets_7acfe87d-652c-41ea-beea-ef307b24d49f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherNoncurrentAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_41dd5298-b56f-4448-a112-49eeafe09a9e" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherNoncurrentAssets_7acfe87d-652c-41ea-beea-ef307b24d49f" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsIncludingGoodwill_08c60500-28d5-40da-ae1e-0b5567da6540" xlink:href="wab-20211231.xsd#wab_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsIncludingGoodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_41dd5298-b56f-4448-a112-49eeafe09a9e" xlink:to="loc_wab_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsIncludingGoodwill_08c60500-28d5-40da-ae1e-0b5567da6540" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilitiesAbstract_9f6292a8-c3fd-45b1-a593-2addd204b259" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilitiesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_cb92234a-c362-450a-b15b-5f3b77a1340e" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilitiesAbstract_9f6292a8-c3fd-45b1-a593-2addd204b259" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities_b47f1b25-4a6c-4714-aa43-643322283a87" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilitiesAbstract_9f6292a8-c3fd-45b1-a593-2addd204b259" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities_b47f1b25-4a6c-4714-aa43-643322283a87" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilities_5fff246f-b6d4-4d37-9da7-ee4d3ae35599" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilitiesAbstract_9f6292a8-c3fd-45b1-a593-2addd204b259" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilities_5fff246f-b6d4-4d37-9da7-ee4d3ae35599" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities_c6043be5-c372-4421-b0a9-8e1be288ffb9" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilitiesAbstract_9f6292a8-c3fd-45b1-a593-2addd204b259" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities_c6043be5-c372-4421-b0a9-8e1be288ffb9" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_85912dc5-2241-4d4c-a5af-ebbc5d8a045e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_cb92234a-c362-450a-b15b-5f3b77a1340e" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedNet_85912dc5-2241-4d4c-a5af-ebbc5d8a045e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_bf47a54d-92da-46b7-9a28-3b4d32105334" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_cb92234a-c362-450a-b15b-5f3b77a1340e" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_bf47a54d-92da-46b7-9a28-3b4d32105334" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_97e524aa-be45-4240-b542-460b3730cfcb" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_bf47a54d-92da-46b7-9a28-3b4d32105334" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_97e524aa-be45-4240-b542-460b3730cfcb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_97e524aa-be45-4240-b542-460b3730cfcb_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_97e524aa-be45-4240-b542-460b3730cfcb" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_97e524aa-be45-4240-b542-460b3730cfcb_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_5a182ae3-2cc8-4e5c-b778-8e41d09c8d87" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_97e524aa-be45-4240-b542-460b3730cfcb" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_5a182ae3-2cc8-4e5c-b778-8e41d09c8d87" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_NordcoMember_66336017-1c95-4b25-9a35-a7065b6781df" xlink:href="wab-20211231.xsd#wab_NordcoMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_5a182ae3-2cc8-4e5c-b778-8e41d09c8d87" xlink:to="loc_wab_NordcoMember_66336017-1c95-4b25-9a35-a7065b6781df" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/ACQUISITIONSSummaryofFairValueofGETransportationAssetsAcquiredandLiabilitiesAssumedDetails" xlink:type="simple" xlink:href="wab-20211231.xsd#ACQUISITIONSSummaryofFairValueofGETransportationAssetsAcquiredandLiabilitiesAssumedDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/ACQUISITIONSSummaryofFairValueofGETransportationAssetsAcquiredandLiabilitiesAssumedDetails" xlink:type="extended" id="ic0f821ffecff48f89b060c222f742e89_ACQUISITIONSSummaryofFairValueofGETransportationAssetsAcquiredandLiabilitiesAssumedDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_72cc46ae-6c46-4d8c-9b66-ec491ecc5abb" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessAcquisitionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_2781c81c-a9fd-49aa-983f-bd8463ff625e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_72cc46ae-6c46-4d8c-9b66-ec491ecc5abb" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_2781c81c-a9fd-49aa-983f-bd8463ff625e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents_7d05fc69-e205-463f-b95a-255b174211fa" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_2781c81c-a9fd-49aa-983f-bd8463ff625e" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCashAndEquivalents_7d05fc69-e205-463f-b95a-255b174211fa" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables_aac80f09-0800-4b1e-8d55-6b2b2b5a8631" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_2781c81c-a9fd-49aa-983f-bd8463ff625e" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsReceivables_aac80f09-0800-4b1e-8d55-6b2b2b5a8631" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory_4dc077fe-ee04-465c-9fd7-0aa5386f0e7e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_2781c81c-a9fd-49aa-983f-bd8463ff625e" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedInventory_4dc077fe-ee04-465c-9fd7-0aa5386f0e7e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsOther_1d1a0b02-778a-4585-a3ca-0d952f92a7e6" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsOther"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_2781c81c-a9fd-49aa-983f-bd8463ff625e" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssetsOther_1d1a0b02-778a-4585-a3ca-0d952f92a7e6" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment_5eb794ec-66d5-4228-8180-d420b8c5f836" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_2781c81c-a9fd-49aa-983f-bd8463ff625e" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment_5eb794ec-66d5-4228-8180-d420b8c5f836" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_c28382d3-b2cf-4398-8b6e-6d5750048cde" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_Goodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_2781c81c-a9fd-49aa-983f-bd8463ff625e" xlink:to="loc_us-gaap_Goodwill_c28382d3-b2cf-4398-8b6e-6d5750048cde" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_1b4d4c03-117f-4335-af47-cf72a5ac7930" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_2781c81c-a9fd-49aa-983f-bd8463ff625e" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_1b4d4c03-117f-4335-af47-cf72a5ac7930" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherNoncurrentAssets_1e9f95ca-5bd3-4012-afea-b7f9cf24f60a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherNoncurrentAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_2781c81c-a9fd-49aa-983f-bd8463ff625e" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherNoncurrentAssets_1e9f95ca-5bd3-4012-afea-b7f9cf24f60a" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsIncludingGoodwill_8578da65-52a2-48d8-b7bb-89a20632572f" xlink:href="wab-20211231.xsd#wab_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsIncludingGoodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsAbstract_2781c81c-a9fd-49aa-983f-bd8463ff625e" xlink:to="loc_wab_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAssetsIncludingGoodwill_8578da65-52a2-48d8-b7bb-89a20632572f" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilitiesAbstract_aab39038-ad93-49bd-8837-5c6566bd8f04" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilitiesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_72cc46ae-6c46-4d8c-9b66-ec491ecc5abb" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilitiesAbstract_aab39038-ad93-49bd-8837-5c6566bd8f04" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities_97404dd4-b435-4902-bfbd-203ba16613b8" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilitiesAbstract_aab39038-ad93-49bd-8837-5c6566bd8f04" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities_97404dd4-b435-4902-bfbd-203ba16613b8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationLiability_9b101a0d-ba82-436a-85ab-c879283394cf" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessCombinationContingentConsiderationLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilitiesAbstract_aab39038-ad93-49bd-8837-5c6566bd8f04" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationLiability_9b101a0d-ba82-436a-85ab-c879283394cf" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther_d72ce823-b5ea-49b8-a435-046f03d6cc62" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilitiesAbstract_aab39038-ad93-49bd-8837-5c6566bd8f04" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther_d72ce823-b5ea-49b8-a435-046f03d6cc62" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities_eac4e62d-e507-4ddd-82e6-817fcbd5e5ee" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilitiesAbstract_aab39038-ad93-49bd-8837-5c6566bd8f04" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities_eac4e62d-e507-4ddd-82e6-817fcbd5e5ee" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedLessNoncontrollingInterest_005d3519-9cc5-4838-b0cb-a2466c754370" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedLessNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_72cc46ae-6c46-4d8c-9b66-ec491ecc5abb" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredGoodwillAndLiabilitiesAssumedLessNoncontrollingInterest_005d3519-9cc5-4838-b0cb-a2466c754370" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationAcquisitionOfLessThan100PercentNoncontrollingInterestFairValue_57683e41-a312-437a-be5d-235609c322a9" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessCombinationAcquisitionOfLessThan100PercentNoncontrollingInterestFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_72cc46ae-6c46-4d8c-9b66-ec491ecc5abb" xlink:to="loc_us-gaap_BusinessCombinationAcquisitionOfLessThan100PercentNoncontrollingInterestFairValue_57683e41-a312-437a-be5d-235609c322a9" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_94739542-3792-484c-b8cd-70f39a227cea" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_72cc46ae-6c46-4d8c-9b66-ec491ecc5abb" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_94739542-3792-484c-b8cd-70f39a227cea" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_078dddcc-832b-46b3-859d-c51a711df2c1" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_94739542-3792-484c-b8cd-70f39a227cea" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_078dddcc-832b-46b3-859d-c51a711df2c1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_078dddcc-832b-46b3-859d-c51a711df2c1_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_078dddcc-832b-46b3-859d-c51a711df2c1" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_078dddcc-832b-46b3-859d-c51a711df2c1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_7b9fd7b8-c596-4600-9bef-f32ff078886d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_078dddcc-832b-46b3-859d-c51a711df2c1" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_7b9fd7b8-c596-4600-9bef-f32ff078886d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_GeneralElectricCompanyMember_bd59db9d-305d-4f45-9a64-a9dbe73b0f02" xlink:href="wab-20211231.xsd#wab_GeneralElectricCompanyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_7b9fd7b8-c596-4600-9bef-f32ff078886d" xlink:to="loc_wab_GeneralElectricCompanyMember_bd59db9d-305d-4f45-9a64-a9dbe73b0f02" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_a6e102d1-dcc8-4335-b721-1a1183d3dcc4" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_94739542-3792-484c-b8cd-70f39a227cea" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_a6e102d1-dcc8-4335-b721-1a1183d3dcc4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_a6e102d1-dcc8-4335-b721-1a1183d3dcc4_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_a6e102d1-dcc8-4335-b721-1a1183d3dcc4" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_a6e102d1-dcc8-4335-b721-1a1183d3dcc4_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_dcc74418-f0a5-4af4-b5e3-3f3e15286ccd" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_a6e102d1-dcc8-4335-b721-1a1183d3dcc4" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_dcc74418-f0a5-4af4-b5e3-3f3e15286ccd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TradeNamesMember_3074851d-bbfb-48fd-abc6-98bdbbc18836" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TradeNamesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_dcc74418-f0a5-4af4-b5e3-3f3e15286ccd" xlink:to="loc_us-gaap_TradeNamesMember_3074851d-bbfb-48fd-abc6-98bdbbc18836" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerRelationshipsMember_e115bd84-2590-4c10-a712-4f6062c6bed6" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CustomerRelationshipsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_dcc74418-f0a5-4af4-b5e3-3f3e15286ccd" xlink:to="loc_us-gaap_CustomerRelationshipsMember_e115bd84-2590-4c10-a712-4f6062c6bed6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntellectualPropertyMember_332df10e-e81d-4813-81ab-cb353607fff2" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IntellectualPropertyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_dcc74418-f0a5-4af4-b5e3-3f3e15286ccd" xlink:to="loc_us-gaap_IntellectualPropertyMember_332df10e-e81d-4813-81ab-cb353607fff2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OrderOrProductionBacklogMember_386f9581-c05a-4f9e-b019-1b111600b956" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OrderOrProductionBacklogMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_dcc74418-f0a5-4af4-b5e3-3f3e15286ccd" xlink:to="loc_us-gaap_OrderOrProductionBacklogMember_386f9581-c05a-4f9e-b019-1b111600b956" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/PROPERTYPLANTEQUIPMENTEstimatedUsefulLivesofPropertyPlantandEquipmentDetails" xlink:type="simple" xlink:href="wab-20211231.xsd#PROPERTYPLANTEQUIPMENTEstimatedUsefulLivesofPropertyPlantandEquipmentDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/PROPERTYPLANTEQUIPMENTEstimatedUsefulLivesofPropertyPlantandEquipmentDetails" xlink:type="extended" id="i3f2259c823e24603891c679a70a4a643_PROPERTYPLANTEQUIPMENTEstimatedUsefulLivesofPropertyPlantandEquipmentDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentLineItems_4b704838-e401-4985-82e8-69cfd606f439" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PropertyPlantAndEquipmentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentUsefulLife_ba1deaed-27d5-43ab-8434-b3dbfeeaf290" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PropertyPlantAndEquipmentUsefulLife"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_4b704838-e401-4985-82e8-69cfd606f439" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentUsefulLife_ba1deaed-27d5-43ab-8434-b3dbfeeaf290" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_29e9bfa4-a410-4f3f-b752-b605f963ef16" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentLineItems_4b704838-e401-4985-82e8-69cfd606f439" xlink:to="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_29e9bfa4-a410-4f3f-b752-b605f963ef16" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_5e1a6bf4-c16b-4d71-8736-314a76876473" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_29e9bfa4-a410-4f3f-b752-b605f963ef16" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_5e1a6bf4-c16b-4d71-8736-314a76876473" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_5e1a6bf4-c16b-4d71-8736-314a76876473_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_5e1a6bf4-c16b-4d71-8736-314a76876473" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_5e1a6bf4-c16b-4d71-8736-314a76876473_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_7653b55a-16e4-42d1-95de-59922952dc5d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentByTypeAxis_5e1a6bf4-c16b-4d71-8736-314a76876473" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_7653b55a-16e4-42d1-95de-59922952dc5d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LandImprovementsMember_ab9b01dc-b41f-42cb-8060-dcf2548aa29f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LandImprovementsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_7653b55a-16e4-42d1-95de-59922952dc5d" xlink:to="loc_us-gaap_LandImprovementsMember_ab9b01dc-b41f-42cb-8060-dcf2548aa29f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BuildingAndBuildingImprovementsMember_418428c8-ae3d-4a60-8085-fbce1b37518b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BuildingAndBuildingImprovementsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_7653b55a-16e4-42d1-95de-59922952dc5d" xlink:to="loc_us-gaap_BuildingAndBuildingImprovementsMember_418428c8-ae3d-4a60-8085-fbce1b37518b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MachineryAndEquipmentMember_088672de-b1eb-4f12-9c7f-2748f83e455f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_MachineryAndEquipmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PropertyPlantAndEquipmentTypeDomain_7653b55a-16e4-42d1-95de-59922952dc5d" xlink:to="loc_us-gaap_MachineryAndEquipmentMember_088672de-b1eb-4f12-9c7f-2748f83e455f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_69ffc480-126d-47ba-886e-ec65c6938f45" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_29e9bfa4-a410-4f3f-b752-b605f963ef16" xlink:to="loc_srt_RangeAxis_69ffc480-126d-47ba-886e-ec65c6938f45" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_69ffc480-126d-47ba-886e-ec65c6938f45_default" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_69ffc480-126d-47ba-886e-ec65c6938f45" xlink:to="loc_srt_RangeMember_69ffc480-126d-47ba-886e-ec65c6938f45_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_672e9dd2-4ca8-4579-9914-7e84a1c056ae" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_69ffc480-126d-47ba-886e-ec65c6938f45" xlink:to="loc_srt_RangeMember_672e9dd2-4ca8-4579-9914-7e84a1c056ae" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_0f35cafe-5666-4b0c-9755-824b0a88045b" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_672e9dd2-4ca8-4579-9914-7e84a1c056ae" xlink:to="loc_srt_MinimumMember_0f35cafe-5666-4b0c-9755-824b0a88045b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_7f936972-01b8-49a0-a1d1-b7d2685cea5b" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_672e9dd2-4ca8-4579-9914-7e84a1c056ae" xlink:to="loc_srt_MaximumMember_7f936972-01b8-49a0-a1d1-b7d2685cea5b" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/INTANGIBLESNarrativeDetails" xlink:type="simple" xlink:href="wab-20211231.xsd#INTANGIBLESNarrativeDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/INTANGIBLESNarrativeDetails" xlink:type="extended" id="i29510c80ff73484cacdf5d8424efc4d5_INTANGIBLESNarrativeDetails">
    <link:loc xlink:type="locator" xlink:label="loc_wab_IntangibleAssetsDisclosureLineItems_d463258c-7694-4af2-b6e0-33f9e5f67077" xlink:href="wab-20211231.xsd#wab_IntangibleAssetsDisclosureLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_GoodwillImpairmentTestWeightOfApproach_adaf7751-0c44-4800-a0a0-199b2869cb69" xlink:href="wab-20211231.xsd#wab_GoodwillImpairmentTestWeightOfApproach"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_wab_IntangibleAssetsDisclosureLineItems_d463258c-7694-4af2-b6e0-33f9e5f67077" xlink:to="loc_wab_GoodwillImpairmentTestWeightOfApproach_adaf7751-0c44-4800-a0a0-199b2869cb69" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IndefiniteLivedTradeNames_538cb602-8e5a-4aa4-8275-c4cc68cea9f7" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IndefiniteLivedTradeNames"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_wab_IntangibleAssetsDisclosureLineItems_d463258c-7694-4af2-b6e0-33f9e5f67077" xlink:to="loc_us-gaap_IndefiniteLivedTradeNames_538cb602-8e5a-4aa4-8275-c4cc68cea9f7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetUsefulLife_2a2b4372-2934-4435-94c6-5e67a6983bf6" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetUsefulLife"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_wab_IntangibleAssetsDisclosureLineItems_d463258c-7694-4af2-b6e0-33f9e5f67077" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetUsefulLife_2a2b4372-2934-4435-94c6-5e67a6983bf6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsRemainingAmortizationPeriod1_1cfff664-2e34-4cf3-b361-e7d899eeea7d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsRemainingAmortizationPeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_wab_IntangibleAssetsDisclosureLineItems_d463258c-7694-4af2-b6e0-33f9e5f67077" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsRemainingAmortizationPeriod1_1cfff664-2e34-4cf3-b361-e7d899eeea7d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfIntangibleAssets_f041acc0-9cb1-4628-85bd-e38fe9f4522d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AmortizationOfIntangibleAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_wab_IntangibleAssetsDisclosureLineItems_d463258c-7694-4af2-b6e0-33f9e5f67077" xlink:to="loc_us-gaap_AmortizationOfIntangibleAssets_f041acc0-9cb1-4628-85bd-e38fe9f4522d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_IntangibleAssetsDisclosureTable_3041013c-a1c0-4b97-98f7-c9d6fdd45f00" xlink:href="wab-20211231.xsd#wab_IntangibleAssetsDisclosureTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_wab_IntangibleAssetsDisclosureLineItems_d463258c-7694-4af2-b6e0-33f9e5f67077" xlink:to="loc_wab_IntangibleAssetsDisclosureTable_3041013c-a1c0-4b97-98f7-c9d6fdd45f00" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_26e3397f-49ad-4a9f-aa3e-b52a64452ae0" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_wab_IntangibleAssetsDisclosureTable_3041013c-a1c0-4b97-98f7-c9d6fdd45f00" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_26e3397f-49ad-4a9f-aa3e-b52a64452ae0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_26e3397f-49ad-4a9f-aa3e-b52a64452ae0_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_26e3397f-49ad-4a9f-aa3e-b52a64452ae0" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_26e3397f-49ad-4a9f-aa3e-b52a64452ae0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_57275ead-ef4c-4e48-af9c-dde9b15c274d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_26e3397f-49ad-4a9f-aa3e-b52a64452ae0" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_57275ead-ef4c-4e48-af9c-dde9b15c274d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TradeNamesMember_0a9c49f0-1ff7-44dc-912e-4f06535be84f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TradeNamesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_57275ead-ef4c-4e48-af9c-dde9b15c274d" xlink:to="loc_us-gaap_TradeNamesMember_0a9c49f0-1ff7-44dc-912e-4f06535be84f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OrderOrProductionBacklogMember_6bb58dd6-8999-46be-b325-da42c271446d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OrderOrProductionBacklogMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_57275ead-ef4c-4e48-af9c-dde9b15c274d" xlink:to="loc_us-gaap_OrderOrProductionBacklogMember_6bb58dd6-8999-46be-b325-da42c271446d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntellectualPropertyMember_c9f3d2b2-ddc1-4a11-a124-18ccade302eb" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IntellectualPropertyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_57275ead-ef4c-4e48-af9c-dde9b15c274d" xlink:to="loc_us-gaap_IntellectualPropertyMember_c9f3d2b2-ddc1-4a11-a124-18ccade302eb" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerRelationshipsMember_5cb5ed79-1bac-4e99-9672-cfc70ef861ea" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CustomerRelationshipsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_57275ead-ef4c-4e48-af9c-dde9b15c274d" xlink:to="loc_us-gaap_CustomerRelationshipsMember_5cb5ed79-1bac-4e99-9672-cfc70ef861ea" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherIntangibleAssetsMember_70bcd8a6-58b1-4710-aeac-097ade35f6c2" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherIntangibleAssetsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_57275ead-ef4c-4e48-af9c-dde9b15c274d" xlink:to="loc_us-gaap_OtherIntangibleAssetsMember_70bcd8a6-58b1-4710-aeac-097ade35f6c2" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationTechniqueAxis_e62b7184-6d9b-4ab2-99d0-cda8c14520ef" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ValuationTechniqueAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_wab_IntangibleAssetsDisclosureTable_3041013c-a1c0-4b97-98f7-c9d6fdd45f00" xlink:to="loc_us-gaap_ValuationTechniqueAxis_e62b7184-6d9b-4ab2-99d0-cda8c14520ef" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationTechniqueDomain_e62b7184-6d9b-4ab2-99d0-cda8c14520ef_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ValuationTechniqueDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ValuationTechniqueAxis_e62b7184-6d9b-4ab2-99d0-cda8c14520ef" xlink:to="loc_us-gaap_ValuationTechniqueDomain_e62b7184-6d9b-4ab2-99d0-cda8c14520ef_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationTechniqueDomain_4b24e7ef-0da3-4c9b-a75c-2082d535e49a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ValuationTechniqueDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ValuationTechniqueAxis_e62b7184-6d9b-4ab2-99d0-cda8c14520ef" xlink:to="loc_us-gaap_ValuationTechniqueDomain_4b24e7ef-0da3-4c9b-a75c-2082d535e49a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationTechniqueDiscountedCashFlowMember_b3aa3b38-6c57-4bf5-9b8f-85ec2b90393f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ValuationTechniqueDiscountedCashFlowMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ValuationTechniqueDomain_4b24e7ef-0da3-4c9b-a75c-2082d535e49a" xlink:to="loc_us-gaap_ValuationTechniqueDiscountedCashFlowMember_b3aa3b38-6c57-4bf5-9b8f-85ec2b90393f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MarketApproachValuationTechniqueMember_fbe18b5b-9bcc-4a6a-b713-95ee3ebc0eeb" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_MarketApproachValuationTechniqueMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ValuationTechniqueDomain_4b24e7ef-0da3-4c9b-a75c-2082d535e49a" xlink:to="loc_us-gaap_MarketApproachValuationTechniqueMember_fbe18b5b-9bcc-4a6a-b713-95ee3ebc0eeb" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/INTANGIBLESChangeintheCarryingAmountofGoodwillbySegmentDetails" xlink:type="simple" xlink:href="wab-20211231.xsd#INTANGIBLESChangeintheCarryingAmountofGoodwillbySegmentDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/INTANGIBLESChangeintheCarryingAmountofGoodwillbySegmentDetails" xlink:type="extended" id="ia008c1fda551405bae00d72593ff9795_INTANGIBLESChangeintheCarryingAmountofGoodwillbySegmentDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillLineItems_d83d2740-11cd-4704-afef-6f2d485d7a8a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_GoodwillLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillRollForward_6bd7707b-e171-43bc-9a41-c34af4189e6f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_GoodwillRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_d83d2740-11cd-4704-afef-6f2d485d7a8a" xlink:to="loc_us-gaap_GoodwillRollForward_6bd7707b-e171-43bc-9a41-c34af4189e6f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_23db39a3-f120-4c75-ac9f-10f13d714b58" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_Goodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_6bd7707b-e171-43bc-9a41-c34af4189e6f" xlink:to="loc_us-gaap_Goodwill_23db39a3-f120-4c75-ac9f-10f13d714b58" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillAcquiredDuringPeriod_b448e1e6-b43e-4318-959c-267ed12814d8" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_GoodwillAcquiredDuringPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_6bd7707b-e171-43bc-9a41-c34af4189e6f" xlink:to="loc_us-gaap_GoodwillAcquiredDuringPeriod_b448e1e6-b43e-4318-959c-267ed12814d8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillWrittenOffRelatedToSaleOfBusinessUnit_2ec8fe76-d3e0-4f90-9fc2-40583a8f0712" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_GoodwillWrittenOffRelatedToSaleOfBusinessUnit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_6bd7707b-e171-43bc-9a41-c34af4189e6f" xlink:to="loc_us-gaap_GoodwillWrittenOffRelatedToSaleOfBusinessUnit_2ec8fe76-d3e0-4f90-9fc2-40583a8f0712" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillForeignCurrencyTranslationGainLoss_09fc0af1-c75e-412b-8cc1-56101f260daf" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_GoodwillForeignCurrencyTranslationGainLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_6bd7707b-e171-43bc-9a41-c34af4189e6f" xlink:to="loc_us-gaap_GoodwillForeignCurrencyTranslationGainLoss_09fc0af1-c75e-412b-8cc1-56101f260daf" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_acd535a6-4b3d-4af5-affe-729295af2116" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_Goodwill"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfGoodwillTable_e5c87af5-176d-4835-ab2b-a3ff7aac5f79" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfGoodwillTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_GoodwillLineItems_d83d2740-11cd-4704-afef-6f2d485d7a8a" xlink:to="loc_us-gaap_ScheduleOfGoodwillTable_e5c87af5-176d-4835-ab2b-a3ff7aac5f79" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_983a4a0b-de7a-410a-8220-eff2dc01603f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfGoodwillTable_e5c87af5-176d-4835-ab2b-a3ff7aac5f79" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_983a4a0b-de7a-410a-8220-eff2dc01603f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_983a4a0b-de7a-410a-8220-eff2dc01603f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_983a4a0b-de7a-410a-8220-eff2dc01603f" xlink:to="loc_us-gaap_SegmentDomain_983a4a0b-de7a-410a-8220-eff2dc01603f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_2934ed57-40be-4385-bfa4-9aff797fd918" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_983a4a0b-de7a-410a-8220-eff2dc01603f" xlink:to="loc_us-gaap_SegmentDomain_2934ed57-40be-4385-bfa4-9aff797fd918" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_FreightSegmentMember_f02b3f84-9812-47f5-899a-f560c271055f" xlink:href="wab-20211231.xsd#wab_FreightSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_2934ed57-40be-4385-bfa4-9aff797fd918" xlink:to="loc_wab_FreightSegmentMember_f02b3f84-9812-47f5-899a-f560c271055f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_TransitSegmentMember_5a3e0932-df52-4510-8862-7a2442c81c2e" xlink:href="wab-20211231.xsd#wab_TransitSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_2934ed57-40be-4385-bfa4-9aff797fd918" xlink:to="loc_wab_TransitSegmentMember_5a3e0932-df52-4510-8862-7a2442c81c2e" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/INTANGIBLESIntangibleAssetsOtherThanGoodwillandTrademarksDetails" xlink:type="simple" xlink:href="wab-20211231.xsd#INTANGIBLESIntangibleAssetsOtherThanGoodwillandTrademarksDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/INTANGIBLESIntangibleAssetsOtherThanGoodwillandTrademarksDetails" xlink:type="extended" id="ifc729e7afcaf491bbda3debdb4885c6e_INTANGIBLESIntangibleAssetsOtherThanGoodwillandTrademarksDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_20d5dcdd-c27d-4fcc-aeee-8468698d1a71" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_aac4a44c-abf3-488d-b710-d87a683541f1" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_20d5dcdd-c27d-4fcc-aeee-8468698d1a71" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_aac4a44c-abf3-488d-b710-d87a683541f1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsNet_80cfd8db-7058-4da8-9f3f-18fbeee9aaea" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_20d5dcdd-c27d-4fcc-aeee-8468698d1a71" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsNet_80cfd8db-7058-4da8-9f3f-18fbeee9aaea" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_68c67d59-eb7f-446b-aee0-7045f61a89c6" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_20d5dcdd-c27d-4fcc-aeee-8468698d1a71" xlink:to="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_68c67d59-eb7f-446b-aee0-7045f61a89c6" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_704880da-a319-4a6b-bc52-92dc0ce05c3e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_68c67d59-eb7f-446b-aee0-7045f61a89c6" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_704880da-a319-4a6b-bc52-92dc0ce05c3e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_704880da-a319-4a6b-bc52-92dc0ce05c3e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_704880da-a319-4a6b-bc52-92dc0ce05c3e" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_704880da-a319-4a6b-bc52-92dc0ce05c3e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_c4a9e81a-14c7-47fa-bc11-267dfd1d147a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_704880da-a319-4a6b-bc52-92dc0ce05c3e" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_c4a9e81a-14c7-47fa-bc11-267dfd1d147a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_IntellectualPropertyPatentsAndOtherMember_83188d77-5aff-4f4c-afe1-e95420f0e602" xlink:href="wab-20211231.xsd#wab_IntellectualPropertyPatentsAndOtherMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_c4a9e81a-14c7-47fa-bc11-267dfd1d147a" xlink:to="loc_wab_IntellectualPropertyPatentsAndOtherMember_83188d77-5aff-4f4c-afe1-e95420f0e602" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OrderOrProductionBacklogMember_860b5a2e-deca-4707-8296-e28443e70caf" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OrderOrProductionBacklogMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_c4a9e81a-14c7-47fa-bc11-267dfd1d147a" xlink:to="loc_us-gaap_OrderOrProductionBacklogMember_860b5a2e-deca-4707-8296-e28443e70caf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerRelationshipsMember_fb2e3d7f-c9c0-42b5-8c7e-2016bacb16f4" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CustomerRelationshipsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_c4a9e81a-14c7-47fa-bc11-267dfd1d147a" xlink:to="loc_us-gaap_CustomerRelationshipsMember_fb2e3d7f-c9c0-42b5-8c7e-2016bacb16f4" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/LONGTERMDEBTScheduleofLongtermDebtDetails" xlink:type="simple" xlink:href="wab-20211231.xsd#LONGTERMDEBTScheduleofLongtermDebtDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/LONGTERMDEBTScheduleofLongtermDebtDetails" xlink:type="extended" id="i11b13a3870cd4ecca9ae6ddd5a827d52_LONGTERMDEBTScheduleofLongtermDebtDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_67a10182-f069-4397-9e28-c509091196ff" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTerm_0c069cd4-7127-48d4-a1dc-df3428539e73" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentTerm"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_67a10182-f069-4397-9e28-c509091196ff" xlink:to="loc_us-gaap_DebtInstrumentTerm_0c069cd4-7127-48d4-a1dc-df3428539e73" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_8d66b41e-6f10-4e2b-b711-8c4c14112eac" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_67a10182-f069-4397-9e28-c509091196ff" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_8d66b41e-6f10-4e2b-b711-8c4c14112eac" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateEffectivePercentage_94baab9e-71e1-4a22-9448-73608bdbf426" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentInterestRateEffectivePercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_67a10182-f069-4397-9e28-c509091196ff" xlink:to="loc_us-gaap_DebtInstrumentInterestRateEffectivePercentage_94baab9e-71e1-4a22-9448-73608bdbf426" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_b8b5f181-652c-4c5c-97ce-d93c0b392e11" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentFaceAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_67a10182-f069-4397-9e28-c509091196ff" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_b8b5f181-652c-4c5c-97ce-d93c0b392e11" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebt_dc6157f9-ea15-4bf1-8051-367367621e3a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_67a10182-f069-4397-9e28-c509091196ff" xlink:to="loc_us-gaap_LongTermDebt_dc6157f9-ea15-4bf1-8051-367367621e3a" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtCurrent_dfc755bd-3a33-4d5c-952a-001d30088a64" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LongTermDebtCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_67a10182-f069-4397-9e28-c509091196ff" xlink:to="loc_us-gaap_LongTermDebtCurrent_dfc755bd-3a33-4d5c-952a-001d30088a64" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtNoncurrent_ef20cace-c0cc-4916-8f77-d965f38d681e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LongTermDebtNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_67a10182-f069-4397-9e28-c509091196ff" xlink:to="loc_us-gaap_LongTermDebtNoncurrent_ef20cace-c0cc-4916-8f77-d965f38d681e" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_5756f12a-7888-427b-8bde-2d17499fe739" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_67a10182-f069-4397-9e28-c509091196ff" xlink:to="loc_us-gaap_DebtInstrumentTable_5756f12a-7888-427b-8bde-2d17499fe739" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_3bce2a65-5146-471c-b60a-4a878c4efc80" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_5756f12a-7888-427b-8bde-2d17499fe739" xlink:to="loc_us-gaap_DebtInstrumentAxis_3bce2a65-5146-471c-b60a-4a878c4efc80" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_3bce2a65-5146-471c-b60a-4a878c4efc80_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_3bce2a65-5146-471c-b60a-4a878c4efc80" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_3bce2a65-5146-471c-b60a-4a878c4efc80_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_d6346083-a09f-4b7b-a68e-e4cccd603f92" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_3bce2a65-5146-471c-b60a-4a878c4efc80" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_d6346083-a09f-4b7b-a68e-e4cccd603f92" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_USDollarDenominatedTermLoansMember_0dba6291-c822-4c32-b874-3a143992728f" xlink:href="wab-20211231.xsd#wab_USDollarDenominatedTermLoansMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_d6346083-a09f-4b7b-a68e-e4cccd603f92" xlink:to="loc_wab_USDollarDenominatedTermLoansMember_0dba6291-c822-4c32-b874-3a143992728f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_MultiCurrencyRevolvingLoanFacilityMember_3e7c5b83-58ed-4dfa-abb1-a24da4b9a632" xlink:href="wab-20211231.xsd#wab_MultiCurrencyRevolvingLoanFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_d6346083-a09f-4b7b-a68e-e4cccd603f92" xlink:to="loc_wab_MultiCurrencyRevolvingLoanFacilityMember_3e7c5b83-58ed-4dfa-abb1-a24da4b9a632" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_A4375PercentSeniorNotesDueTwoThousandAndTwentyThreeMember_e7a17e71-4166-4a31-93fd-68cd72a1077c" xlink:href="wab-20211231.xsd#wab_A4375PercentSeniorNotesDueTwoThousandAndTwentyThreeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_d6346083-a09f-4b7b-a68e-e4cccd603f92" xlink:to="loc_wab_A4375PercentSeniorNotesDueTwoThousandAndTwentyThreeMember_e7a17e71-4166-4a31-93fd-68cd72a1077c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_A4150PercentSeniorNotesDueTwoThousandAndTwentyFourMember_3d8a152c-2db0-4506-b78c-624dbbbb8901" xlink:href="wab-20211231.xsd#wab_A4150PercentSeniorNotesDueTwoThousandAndTwentyFourMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_d6346083-a09f-4b7b-a68e-e4cccd603f92" xlink:to="loc_wab_A4150PercentSeniorNotesDueTwoThousandAndTwentyFourMember_3d8a152c-2db0-4506-b78c-624dbbbb8901" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_A32000PercentSeniorNotesDueTwoThousandAndTwentyFiveMember_ce7e9ba1-db9f-4970-8d23-0d03d826be44" xlink:href="wab-20211231.xsd#wab_A32000PercentSeniorNotesDueTwoThousandAndTwentyFiveMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_d6346083-a09f-4b7b-a68e-e4cccd603f92" xlink:to="loc_wab_A32000PercentSeniorNotesDueTwoThousandAndTwentyFiveMember_ce7e9ba1-db9f-4970-8d23-0d03d826be44" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_A3.45PercentSeniorNotesDueTwoThousandandTwentySixMember_6c57d05e-4f7a-4fcf-a433-561710be9589" xlink:href="wab-20211231.xsd#wab_A3.45PercentSeniorNotesDueTwoThousandandTwentySixMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_d6346083-a09f-4b7b-a68e-e4cccd603f92" xlink:to="loc_wab_A3.45PercentSeniorNotesDueTwoThousandandTwentySixMember_6c57d05e-4f7a-4fcf-a433-561710be9589" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_A125PercentSeniorNotesDueTwoThousandAndTwentySixMember_9cb09f97-fddf-4c24-be5c-59128e592783" xlink:href="wab-20211231.xsd#wab_A125PercentSeniorNotesDueTwoThousandAndTwentySixMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_d6346083-a09f-4b7b-a68e-e4cccd603f92" xlink:to="loc_wab_A125PercentSeniorNotesDueTwoThousandAndTwentySixMember_9cb09f97-fddf-4c24-be5c-59128e592783" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_A470PercentSeniorNotesDueTwoThousandAndTwentySixMember_78eda8f4-ddb0-41b2-8be2-434f66aa3863" xlink:href="wab-20211231.xsd#wab_A470PercentSeniorNotesDueTwoThousandAndTwentySixMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_d6346083-a09f-4b7b-a68e-e4cccd603f92" xlink:to="loc_wab_A470PercentSeniorNotesDueTwoThousandAndTwentySixMember_78eda8f4-ddb0-41b2-8be2-434f66aa3863" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_f4cadf64-78ba-44d5-816f-bc6a69c0f4d8" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_5756f12a-7888-427b-8bde-2d17499fe739" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_f4cadf64-78ba-44d5-816f-bc6a69c0f4d8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_f4cadf64-78ba-44d5-816f-bc6a69c0f4d8_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_f4cadf64-78ba-44d5-816f-bc6a69c0f4d8" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_f4cadf64-78ba-44d5-816f-bc6a69c0f4d8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_5d940c42-d3c5-426f-bb27-3865c68aee55" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_f4cadf64-78ba-44d5-816f-bc6a69c0f4d8" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_5d940c42-d3c5-426f-bb27-3865c68aee55" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditMember_1200ee55-789f-4671-aad0-469af9a7409b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LineOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_5d940c42-d3c5-426f-bb27-3865c68aee55" xlink:to="loc_us-gaap_LineOfCreditMember_1200ee55-789f-4671-aad0-469af9a7409b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeniorNotesMember_4d3abc65-b961-4b1b-b7bd-c6611ae06bbd" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SeniorNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_5d940c42-d3c5-426f-bb27-3865c68aee55" xlink:to="loc_us-gaap_SeniorNotesMember_4d3abc65-b961-4b1b-b7bd-c6611ae06bbd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherDebtSecuritiesMember_4fd1b333-3293-4d07-9afd-57090d8e911c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherDebtSecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_5d940c42-d3c5-426f-bb27-3865c68aee55" xlink:to="loc_us-gaap_OtherDebtSecuritiesMember_4fd1b333-3293-4d07-9afd-57090d8e911c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_34bcd722-8678-4a1e-a471-c5d3acb11d92" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CreditFacilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_5756f12a-7888-427b-8bde-2d17499fe739" xlink:to="loc_us-gaap_CreditFacilityAxis_34bcd722-8678-4a1e-a471-c5d3acb11d92" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_34bcd722-8678-4a1e-a471-c5d3acb11d92_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_34bcd722-8678-4a1e-a471-c5d3acb11d92" xlink:to="loc_us-gaap_CreditFacilityDomain_34bcd722-8678-4a1e-a471-c5d3acb11d92_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_b2cc028d-e99d-4c32-a508-9d66096d38e6" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_34bcd722-8678-4a1e-a471-c5d3acb11d92" xlink:to="loc_us-gaap_CreditFacilityDomain_b2cc028d-e99d-4c32-a508-9d66096d38e6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_d370ea9b-1d61-485a-a513-e7c6987b63a5" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RevolvingCreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_b2cc028d-e99d-4c32-a508-9d66096d38e6" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_d370ea9b-1d61-485a-a513-e7c6987b63a5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByMeasurementBasisAxis_0927dfbf-50f0-49ef-810d-829997512aab" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueByMeasurementBasisAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_5756f12a-7888-427b-8bde-2d17499fe739" xlink:to="loc_us-gaap_FairValueByMeasurementBasisAxis_0927dfbf-50f0-49ef-810d-829997512aab" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_0927dfbf-50f0-49ef-810d-829997512aab_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PortionAtFairValueFairValueDisclosureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByMeasurementBasisAxis_0927dfbf-50f0-49ef-810d-829997512aab" xlink:to="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_0927dfbf-50f0-49ef-810d-829997512aab_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueDisclosureItemAmountsDomain_b1ea17c7-87b3-4a4f-9438-0ee5c7324f33" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueDisclosureItemAmountsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByMeasurementBasisAxis_0927dfbf-50f0-49ef-810d-829997512aab" xlink:to="loc_us-gaap_FairValueDisclosureItemAmountsDomain_b1ea17c7-87b3-4a4f-9438-0ee5c7324f33" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_c134f965-368b-4449-9136-941da6e39ec5" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PortionAtFairValueFairValueDisclosureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueDisclosureItemAmountsDomain_b1ea17c7-87b3-4a4f-9438-0ee5c7324f33" xlink:to="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_c134f965-368b-4449-9136-941da6e39ec5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EstimateOfFairValueFairValueDisclosureMember_69fef639-37ca-4d5e-a373-9815e391d02a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EstimateOfFairValueFairValueDisclosureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueDisclosureItemAmountsDomain_b1ea17c7-87b3-4a4f-9438-0ee5c7324f33" xlink:to="loc_us-gaap_EstimateOfFairValueFairValueDisclosureMember_69fef639-37ca-4d5e-a373-9815e391d02a" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/LONGTERMDEBTNarrativeDetails" xlink:type="simple" xlink:href="wab-20211231.xsd#LONGTERMDEBTNarrativeDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/LONGTERMDEBTNarrativeDetails" xlink:type="extended" id="ib1ac8976b33243c3ba3b66dcdc57a77c_LONGTERMDEBTNarrativeDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_336bea2b-450e-45e6-9acc-641dbbca4b19" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredFinanceCostsNet_859374b7-455a-4552-98f5-fff1ced206a9" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredFinanceCostsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_336bea2b-450e-45e6-9acc-641dbbca4b19" xlink:to="loc_us-gaap_DeferredFinanceCostsNet_859374b7-455a-4552-98f5-fff1ced206a9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtWeightedAverageInterestRate_c12845b0-c3df-4c2e-9ece-de831f01ee8c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LongtermDebtWeightedAverageInterestRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_336bea2b-450e-45e6-9acc-641dbbca4b19" xlink:to="loc_us-gaap_LongtermDebtWeightedAverageInterestRate_c12845b0-c3df-4c2e-9ece-de831f01ee8c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_a426dadc-58ca-42df-867b-98bd14d73b55" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_336bea2b-450e-45e6-9acc-641dbbca4b19" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_a426dadc-58ca-42df-867b-98bd14d73b55" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_DebtInstrumentRestrictiveCovenantsLeverageRatioMaximum_8832989f-f22b-4643-b319-7ceda25425ac" xlink:href="wab-20211231.xsd#wab_DebtInstrumentRestrictiveCovenantsLeverageRatioMaximum"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_336bea2b-450e-45e6-9acc-641dbbca4b19" xlink:to="loc_wab_DebtInstrumentRestrictiveCovenantsLeverageRatioMaximum_8832989f-f22b-4643-b319-7ceda25425ac" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTerm_6bccd49a-52c9-4840-b6c1-2407d351dc00" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentTerm"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_336bea2b-450e-45e6-9acc-641dbbca4b19" xlink:to="loc_us-gaap_DebtInstrumentTerm_6bccd49a-52c9-4840-b6c1-2407d351dc00" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebt_dca917a2-4620-4cdb-b452-034d0e77aff9" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_336bea2b-450e-45e6-9acc-641dbbca4b19" xlink:to="loc_us-gaap_LongTermDebt_dca917a2-4620-4cdb-b452-034d0e77aff9" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_971b83f9-9898-4ab0-be03-af7628fd178c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_336bea2b-450e-45e6-9acc-641dbbca4b19" xlink:to="loc_us-gaap_DebtInstrumentInterestRateStatedPercentage_971b83f9-9898-4ab0-be03-af7628fd178c" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentRedemptionPricePercentage_7279f343-6575-4f6b-aec9-a6e063eaf258" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentRedemptionPricePercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_336bea2b-450e-45e6-9acc-641dbbca4b19" xlink:to="loc_us-gaap_DebtInstrumentRedemptionPricePercentage_7279f343-6575-4f6b-aec9-a6e063eaf258" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_688748f2-804a-405a-a76a-b99cb7168ff8" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentFaceAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_336bea2b-450e-45e6-9acc-641dbbca4b19" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_688748f2-804a-405a-a76a-b99cb7168ff8" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredFinanceCostsGross_6691502e-55b7-421b-98a4-32b40b25a70c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredFinanceCostsGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_336bea2b-450e-45e6-9acc-641dbbca4b19" xlink:to="loc_us-gaap_DeferredFinanceCostsGross_6691502e-55b7-421b-98a4-32b40b25a70c" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProceedsFromIssuanceOfDebt_7dd79b78-f4da-4f07-b7b8-3dee19b4b431" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProceedsFromIssuanceOfDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_336bea2b-450e-45e6-9acc-641dbbca4b19" xlink:to="loc_us-gaap_ProceedsFromIssuanceOfDebt_7dd79b78-f4da-4f07-b7b8-3dee19b4b431" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LettersOfCreditOutstandingAmount_1e1c6aed-b586-48bf-b2e4-4d7d6dc8bad3" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LettersOfCreditOutstandingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_336bea2b-450e-45e6-9acc-641dbbca4b19" xlink:to="loc_us-gaap_LettersOfCreditOutstandingAmount_1e1c6aed-b586-48bf-b2e4-4d7d6dc8bad3" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_02747a2c-a917-4ed0-88c2-6e74d6f0bfab" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_336bea2b-450e-45e6-9acc-641dbbca4b19" xlink:to="loc_us-gaap_DebtInstrumentTable_02747a2c-a917-4ed0-88c2-6e74d6f0bfab" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_a126f54a-67b2-49a6-9bb6-d4fb08d1de3a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_02747a2c-a917-4ed0-88c2-6e74d6f0bfab" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_a126f54a-67b2-49a6-9bb6-d4fb08d1de3a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_a126f54a-67b2-49a6-9bb6-d4fb08d1de3a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_a126f54a-67b2-49a6-9bb6-d4fb08d1de3a" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_a126f54a-67b2-49a6-9bb6-d4fb08d1de3a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_1f48221c-9801-462e-a254-809a58b3d295" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_a126f54a-67b2-49a6-9bb6-d4fb08d1de3a" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_1f48221c-9801-462e-a254-809a58b3d295" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditMember_44c97941-a49a-4d9a-adfc-4ab52bb20612" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LineOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_1f48221c-9801-462e-a254-809a58b3d295" xlink:to="loc_us-gaap_LineOfCreditMember_44c97941-a49a-4d9a-adfc-4ab52bb20612" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SeniorNotesMember_3b6a0018-16e2-40a6-866c-e5f1c531f553" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SeniorNotesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_1f48221c-9801-462e-a254-809a58b3d295" xlink:to="loc_us-gaap_SeniorNotesMember_3b6a0018-16e2-40a6-866c-e5f1c531f553" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_44e04345-dfef-43e5-8d64-b71377c5863e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_02747a2c-a917-4ed0-88c2-6e74d6f0bfab" xlink:to="loc_us-gaap_DebtInstrumentAxis_44e04345-dfef-43e5-8d64-b71377c5863e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_44e04345-dfef-43e5-8d64-b71377c5863e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_44e04345-dfef-43e5-8d64-b71377c5863e" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_44e04345-dfef-43e5-8d64-b71377c5863e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_181ebfad-d429-477f-bbac-03889c5d7ba1" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_44e04345-dfef-43e5-8d64-b71377c5863e" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_181ebfad-d429-477f-bbac-03889c5d7ba1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_TwoThousandandEighteenRefinancingAgreementMember_3a7c8286-cd53-4a03-b887-eec6294d40b3" xlink:href="wab-20211231.xsd#wab_TwoThousandandEighteenRefinancingAgreementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_181ebfad-d429-477f-bbac-03889c5d7ba1" xlink:to="loc_wab_TwoThousandandEighteenRefinancingAgreementMember_3a7c8286-cd53-4a03-b887-eec6294d40b3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_TermLoanMember_37a864fb-c3f4-4589-827a-ea1998792d87" xlink:href="wab-20211231.xsd#wab_TermLoanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_181ebfad-d429-477f-bbac-03889c5d7ba1" xlink:to="loc_wab_TermLoanMember_37a864fb-c3f4-4589-827a-ea1998792d87" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_A4375PercentSeniorNotesDueTwoThousandAndTwentyThreeMember_e287fcea-bcb1-41f1-91fd-002955058c26" xlink:href="wab-20211231.xsd#wab_A4375PercentSeniorNotesDueTwoThousandAndTwentyThreeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_181ebfad-d429-477f-bbac-03889c5d7ba1" xlink:to="loc_wab_A4375PercentSeniorNotesDueTwoThousandAndTwentyThreeMember_e287fcea-bcb1-41f1-91fd-002955058c26" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_A4150PercentSeniorNotesDueTwoThousandAndTwentyFourMember_e0480c86-4a77-4792-b464-f0cc5c453ce1" xlink:href="wab-20211231.xsd#wab_A4150PercentSeniorNotesDueTwoThousandAndTwentyFourMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_181ebfad-d429-477f-bbac-03889c5d7ba1" xlink:to="loc_wab_A4150PercentSeniorNotesDueTwoThousandAndTwentyFourMember_e0480c86-4a77-4792-b464-f0cc5c453ce1" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_A32000PercentSeniorNotesDueTwoThousandAndTwentyFiveMember_725496ce-d2c0-4f1d-94db-f28a25314988" xlink:href="wab-20211231.xsd#wab_A32000PercentSeniorNotesDueTwoThousandAndTwentyFiveMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_181ebfad-d429-477f-bbac-03889c5d7ba1" xlink:to="loc_wab_A32000PercentSeniorNotesDueTwoThousandAndTwentyFiveMember_725496ce-d2c0-4f1d-94db-f28a25314988" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_A3.45PercentSeniorNotesDueTwoThousandandTwentySixMember_5664a5cc-dd86-4e81-b870-d4cdc83083bb" xlink:href="wab-20211231.xsd#wab_A3.45PercentSeniorNotesDueTwoThousandandTwentySixMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_181ebfad-d429-477f-bbac-03889c5d7ba1" xlink:to="loc_wab_A3.45PercentSeniorNotesDueTwoThousandandTwentySixMember_5664a5cc-dd86-4e81-b870-d4cdc83083bb" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_A125PercentSeniorNotesDueTwoThousandAndTwentySixMember_6ad7640f-ff44-4bf1-8070-27955d6f61d6" xlink:href="wab-20211231.xsd#wab_A125PercentSeniorNotesDueTwoThousandAndTwentySixMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_181ebfad-d429-477f-bbac-03889c5d7ba1" xlink:to="loc_wab_A125PercentSeniorNotesDueTwoThousandAndTwentySixMember_6ad7640f-ff44-4bf1-8070-27955d6f61d6" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_A470PercentSeniorNotesDueTwoThousandAndTwentySixMember_7a069eb9-aa1c-489a-9ea2-91eedf4e0b91" xlink:href="wab-20211231.xsd#wab_A470PercentSeniorNotesDueTwoThousandAndTwentySixMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_181ebfad-d429-477f-bbac-03889c5d7ba1" xlink:to="loc_wab_A470PercentSeniorNotesDueTwoThousandAndTwentySixMember_7a069eb9-aa1c-489a-9ea2-91eedf4e0b91" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_7f9f7ce4-932f-486d-8171-10ffe938f67b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CreditFacilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_02747a2c-a917-4ed0-88c2-6e74d6f0bfab" xlink:to="loc_us-gaap_CreditFacilityAxis_7f9f7ce4-932f-486d-8171-10ffe938f67b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_7f9f7ce4-932f-486d-8171-10ffe938f67b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_7f9f7ce4-932f-486d-8171-10ffe938f67b" xlink:to="loc_us-gaap_CreditFacilityDomain_7f9f7ce4-932f-486d-8171-10ffe938f67b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_c1ef1aeb-1f46-4b5e-96ee-afe2240bce94" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_7f9f7ce4-932f-486d-8171-10ffe938f67b" xlink:to="loc_us-gaap_CreditFacilityDomain_c1ef1aeb-1f46-4b5e-96ee-afe2240bce94" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_c4c3acba-38f5-4417-b3ad-bd9099f0b7a0" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RevolvingCreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_c1ef1aeb-1f46-4b5e-96ee-afe2240bce94" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_c4c3acba-38f5-4417-b3ad-bd9099f0b7a0" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_SwingLineSubFacilityMember_bc04e40e-f6b7-4437-bc25-1982530bebe3" xlink:href="wab-20211231.xsd#wab_SwingLineSubFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_c1ef1aeb-1f46-4b5e-96ee-afe2240bce94" xlink:to="loc_wab_SwingLineSubFacilityMember_bc04e40e-f6b7-4437-bc25-1982530bebe3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LetterOfCreditMember_1f043a14-c9d3-4202-ab19-021df1f193b5" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LetterOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_c1ef1aeb-1f46-4b5e-96ee-afe2240bce94" xlink:to="loc_us-gaap_LetterOfCreditMember_1f043a14-c9d3-4202-ab19-021df1f193b5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_TermLoanMember_8fb306a1-4699-4188-be0f-b42a05e8ecb1" xlink:href="wab-20211231.xsd#wab_TermLoanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_c1ef1aeb-1f46-4b5e-96ee-afe2240bce94" xlink:to="loc_wab_TermLoanMember_8fb306a1-4699-4188-be0f-b42a05e8ecb1" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_DebtInstrumentCovenantPeriodAxis_6fa20735-93de-4750-802b-281270518cd9" xlink:href="wab-20211231.xsd#wab_DebtInstrumentCovenantPeriodAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_02747a2c-a917-4ed0-88c2-6e74d6f0bfab" xlink:to="loc_wab_DebtInstrumentCovenantPeriodAxis_6fa20735-93de-4750-802b-281270518cd9" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_DebtInstrumentCovenantPeriodDomain_6fa20735-93de-4750-802b-281270518cd9_default" xlink:href="wab-20211231.xsd#wab_DebtInstrumentCovenantPeriodDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_wab_DebtInstrumentCovenantPeriodAxis_6fa20735-93de-4750-802b-281270518cd9" xlink:to="loc_wab_DebtInstrumentCovenantPeriodDomain_6fa20735-93de-4750-802b-281270518cd9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_DebtInstrumentCovenantPeriodDomain_3f00501a-aa05-45b9-82f6-284e682bb61c" xlink:href="wab-20211231.xsd#wab_DebtInstrumentCovenantPeriodDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_wab_DebtInstrumentCovenantPeriodAxis_6fa20735-93de-4750-802b-281270518cd9" xlink:to="loc_wab_DebtInstrumentCovenantPeriodDomain_3f00501a-aa05-45b9-82f6-284e682bb61c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_DebtInstrumentCovenantPeriodOneMember_fc2ffa71-6389-4a82-80fa-d3c7a6d6c2c9" xlink:href="wab-20211231.xsd#wab_DebtInstrumentCovenantPeriodOneMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_wab_DebtInstrumentCovenantPeriodDomain_3f00501a-aa05-45b9-82f6-284e682bb61c" xlink:to="loc_wab_DebtInstrumentCovenantPeriodOneMember_fc2ffa71-6389-4a82-80fa-d3c7a6d6c2c9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_DebtInstrumentCovenantPeriodTwoMember_7cd0f6bc-0dbe-4fdc-8bae-f73f6fc593cb" xlink:href="wab-20211231.xsd#wab_DebtInstrumentCovenantPeriodTwoMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_wab_DebtInstrumentCovenantPeriodDomain_3f00501a-aa05-45b9-82f6-284e682bb61c" xlink:to="loc_wab_DebtInstrumentCovenantPeriodTwoMember_7cd0f6bc-0dbe-4fdc-8bae-f73f6fc593cb" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/LONGTERMDEBTInterestCoverageRatioLeverageRatioDetails" xlink:type="simple" xlink:href="wab-20211231.xsd#LONGTERMDEBTInterestCoverageRatioLeverageRatioDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/LONGTERMDEBTInterestCoverageRatioLeverageRatioDetails" xlink:type="extended" id="i652ff2a360bb437290cd3ede0bdb1df6_LONGTERMDEBTInterestCoverageRatioLeverageRatioDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_73f87ee9-725b-4a0c-9d29-ee63052af11f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_DebtInstrumentRestrictiveCovenantsEBITDAtoInterestExpenseRatioMinimum_32c68901-3dfe-4289-806f-8fb40c7c4db8" xlink:href="wab-20211231.xsd#wab_DebtInstrumentRestrictiveCovenantsEBITDAtoInterestExpenseRatioMinimum"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_73f87ee9-725b-4a0c-9d29-ee63052af11f" xlink:to="loc_wab_DebtInstrumentRestrictiveCovenantsEBITDAtoInterestExpenseRatioMinimum_32c68901-3dfe-4289-806f-8fb40c7c4db8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_DebtInstrumentRestrictiveCovenantsLeverageRatioMaximum_e0579c13-1f6d-4178-bd02-be4300f8f2f2" xlink:href="wab-20211231.xsd#wab_DebtInstrumentRestrictiveCovenantsLeverageRatioMaximum"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_73f87ee9-725b-4a0c-9d29-ee63052af11f" xlink:to="loc_wab_DebtInstrumentRestrictiveCovenantsLeverageRatioMaximum_e0579c13-1f6d-4178-bd02-be4300f8f2f2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_623fce53-5096-4fe4-9f03-5c8218cf7852" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_73f87ee9-725b-4a0c-9d29-ee63052af11f" xlink:to="loc_us-gaap_DebtInstrumentTable_623fce53-5096-4fe4-9f03-5c8218cf7852" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_82c7fb76-9267-44d9-98e2-c37fa3f47fab" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_623fce53-5096-4fe4-9f03-5c8218cf7852" xlink:to="loc_us-gaap_DebtInstrumentAxis_82c7fb76-9267-44d9-98e2-c37fa3f47fab" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_82c7fb76-9267-44d9-98e2-c37fa3f47fab_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_82c7fb76-9267-44d9-98e2-c37fa3f47fab" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_82c7fb76-9267-44d9-98e2-c37fa3f47fab_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_1d268e29-bc05-4e17-b40c-c250559eeb6f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_82c7fb76-9267-44d9-98e2-c37fa3f47fab" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_1d268e29-bc05-4e17-b40c-c250559eeb6f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_TwoThousandandEighteenRefinancingAgreementMember_1673a0a3-27b2-4d42-98a7-84ac2f49cfd7" xlink:href="wab-20211231.xsd#wab_TwoThousandandEighteenRefinancingAgreementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_1d268e29-bc05-4e17-b40c-c250559eeb6f" xlink:to="loc_wab_TwoThousandandEighteenRefinancingAgreementMember_1673a0a3-27b2-4d42-98a7-84ac2f49cfd7" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/LONGTERMDEBTScheduleofLineofCreditFacilitiesDetails" xlink:type="simple" xlink:href="wab-20211231.xsd#LONGTERMDEBTScheduleofLineofCreditFacilitiesDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/LONGTERMDEBTScheduleofLineofCreditFacilitiesDetails" xlink:type="extended" id="i7c7529d1078b4b8196e9622b622f3e5f_LONGTERMDEBTScheduleofLineofCreditFacilitiesDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_16e3f6df-2b0b-4936-ac2c-ce0c5b597e05" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_15514703-6d3e-41fe-a68f-38b3bea6d7e3" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_16e3f6df-2b0b-4936-ac2c-ce0c5b597e05" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_15514703-6d3e-41fe-a68f-38b3bea6d7e3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LettersOfCreditOutstandingAmount_fc484ee6-1ace-4ec9-be61-3cff8bb8e6a6" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LettersOfCreditOutstandingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_16e3f6df-2b0b-4936-ac2c-ce0c5b597e05" xlink:to="loc_us-gaap_LettersOfCreditOutstandingAmount_fc484ee6-1ace-4ec9-be61-3cff8bb8e6a6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity_5a8b24bc-aaa0-48f9-8375-b980e620e67b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_16e3f6df-2b0b-4936-ac2c-ce0c5b597e05" xlink:to="loc_us-gaap_LineOfCreditFacilityRemainingBorrowingCapacity_5a8b24bc-aaa0-48f9-8375-b980e620e67b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_283cb223-6159-4d34-bb5d-361b6f65e11f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_16e3f6df-2b0b-4936-ac2c-ce0c5b597e05" xlink:to="loc_us-gaap_DebtInstrumentTable_283cb223-6159-4d34-bb5d-361b6f65e11f" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_47bd0cae-2aae-4ddf-897e-0ee6f5591214" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_283cb223-6159-4d34-bb5d-361b6f65e11f" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_47bd0cae-2aae-4ddf-897e-0ee6f5591214" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_47bd0cae-2aae-4ddf-897e-0ee6f5591214_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_47bd0cae-2aae-4ddf-897e-0ee6f5591214" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_47bd0cae-2aae-4ddf-897e-0ee6f5591214_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_77c45826-a7a6-4167-a60f-ca47577f4ff2" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_47bd0cae-2aae-4ddf-897e-0ee6f5591214" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_77c45826-a7a6-4167-a60f-ca47577f4ff2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditMember_897df173-6f26-43ab-8bd3-29ec4099f448" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LineOfCreditMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_77c45826-a7a6-4167-a60f-ca47577f4ff2" xlink:to="loc_us-gaap_LineOfCreditMember_897df173-6f26-43ab-8bd3-29ec4099f448" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_4664d572-1008-41de-bf82-ca0bfe553eb2" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CreditFacilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_283cb223-6159-4d34-bb5d-361b6f65e11f" xlink:to="loc_us-gaap_CreditFacilityAxis_4664d572-1008-41de-bf82-ca0bfe553eb2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_4664d572-1008-41de-bf82-ca0bfe553eb2_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_4664d572-1008-41de-bf82-ca0bfe553eb2" xlink:to="loc_us-gaap_CreditFacilityDomain_4664d572-1008-41de-bf82-ca0bfe553eb2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_862d96aa-44a3-48b3-8b62-29e4d05dc2b3" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_4664d572-1008-41de-bf82-ca0bfe553eb2" xlink:to="loc_us-gaap_CreditFacilityDomain_862d96aa-44a3-48b3-8b62-29e4d05dc2b3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_8df2241a-6358-4106-8332-1de08631f6a3" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RevolvingCreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_862d96aa-44a3-48b3-8b62-29e4d05dc2b3" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_8df2241a-6358-4106-8332-1de08631f6a3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_538517b6-b4c0-4d2b-b850-4a7585816652" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_283cb223-6159-4d34-bb5d-361b6f65e11f" xlink:to="loc_us-gaap_DebtInstrumentAxis_538517b6-b4c0-4d2b-b850-4a7585816652" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_538517b6-b4c0-4d2b-b850-4a7585816652_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_538517b6-b4c0-4d2b-b850-4a7585816652" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_538517b6-b4c0-4d2b-b850-4a7585816652_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_80db75e5-4fb0-441c-84b2-7aa0a6a64977" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_538517b6-b4c0-4d2b-b850-4a7585816652" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_80db75e5-4fb0-441c-84b2-7aa0a6a64977" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_TwoThousandandEighteenRefinancingAgreementMember_d5d148d9-5944-4161-bb7b-25c133ae76b6" xlink:href="wab-20211231.xsd#wab_TwoThousandandEighteenRefinancingAgreementMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_80db75e5-4fb0-441c-84b2-7aa0a6a64977" xlink:to="loc_wab_TwoThousandandEighteenRefinancingAgreementMember_d5d148d9-5944-4161-bb7b-25c133ae76b6" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/EMPLOYEEBENEFITPLANSObligationsandFundedStatusDetails" xlink:type="simple" xlink:href="wab-20211231.xsd#EMPLOYEEBENEFITPLANSObligationsandFundedStatusDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/EMPLOYEEBENEFITPLANSObligationsandFundedStatusDetails" xlink:type="extended" id="if015475d5eb54401a945a3648693a419_EMPLOYEEBENEFITPLANSObligationsandFundedStatusDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_c657e43e-06ec-4f3e-9844-2bfaea302bb6" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_4c8b2f7a-d318-48d6-930d-0e2ec44a46a6" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_c657e43e-06ec-4f3e-9844-2bfaea302bb6" xlink:to="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_4c8b2f7a-d318-48d6-930d-0e2ec44a46a6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanBenefitObligation_b7922b00-778f-4330-b967-84f123fa8ff2" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanBenefitObligation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_4c8b2f7a-d318-48d6-930d-0e2ec44a46a6" xlink:to="loc_us-gaap_DefinedBenefitPlanBenefitObligation_b7922b00-778f-4330-b967-84f123fa8ff2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanServiceCost_e9214459-2272-4a31-82f5-9781838dfc5a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanServiceCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_4c8b2f7a-d318-48d6-930d-0e2ec44a46a6" xlink:to="loc_us-gaap_DefinedBenefitPlanServiceCost_e9214459-2272-4a31-82f5-9781838dfc5a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanInterestCost_507a963d-a3a7-4d40-9caf-cbe8e09c4002" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanInterestCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_4c8b2f7a-d318-48d6-930d-0e2ec44a46a6" xlink:to="loc_us-gaap_DefinedBenefitPlanInterestCost_507a963d-a3a7-4d40-9caf-cbe8e09c4002" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanBenefitObligationContributionsByPlanParticipant_443efe41-5363-40e5-8fc7-a525d042486d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanBenefitObligationContributionsByPlanParticipant"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_4c8b2f7a-d318-48d6-930d-0e2ec44a46a6" xlink:to="loc_us-gaap_DefinedBenefitPlanBenefitObligationContributionsByPlanParticipant_443efe41-5363-40e5-8fc7-a525d042486d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_DefinedBenefitPlanCurtailmentsAndAmendments_7657bfb5-6e2e-410d-8a4a-0fc65fee77f3" xlink:href="wab-20211231.xsd#wab_DefinedBenefitPlanCurtailmentsAndAmendments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_4c8b2f7a-d318-48d6-930d-0e2ec44a46a6" xlink:to="loc_wab_DefinedBenefitPlanCurtailmentsAndAmendments_7657bfb5-6e2e-410d-8a4a-0fc65fee77f3" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanBenefitObligationBenefitsPaid_2ca73c7c-5d13-4562-bf1f-9505cb468d5d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanBenefitObligationBenefitsPaid"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_4c8b2f7a-d318-48d6-930d-0e2ec44a46a6" xlink:to="loc_us-gaap_DefinedBenefitPlanBenefitObligationBenefitsPaid_2ca73c7c-5d13-4562-bf1f-9505cb468d5d" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanActuarialGainLoss_829f666d-0dcb-44ee-9ce7-626487bf7a32" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanActuarialGainLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_4c8b2f7a-d318-48d6-930d-0e2ec44a46a6" xlink:to="loc_us-gaap_DefinedBenefitPlanActuarialGainLoss_829f666d-0dcb-44ee-9ce7-626487bf7a32" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanForeignCurrencyExchangeRateChangesBenefitObligation_f1bf97af-b248-4c7b-a772-b101e62457d0" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanForeignCurrencyExchangeRateChangesBenefitObligation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInBenefitObligationRollForward_4c8b2f7a-d318-48d6-930d-0e2ec44a46a6" xlink:to="loc_us-gaap_DefinedBenefitPlanForeignCurrencyExchangeRateChangesBenefitObligation_f1bf97af-b248-4c7b-a772-b101e62457d0" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanBenefitObligation_d21cb8df-3662-438b-932b-1b0131741a16" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanBenefitObligation"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward_edfbed3e-fcd9-4a89-97cd-f5d2c8d9acff" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_c657e43e-06ec-4f3e-9844-2bfaea302bb6" xlink:to="loc_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward_edfbed3e-fcd9-4a89-97cd-f5d2c8d9acff" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_f8f94999-bc96-4c41-8585-4c37eeaf2ee3" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanFairValueOfPlanAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward_edfbed3e-fcd9-4a89-97cd-f5d2c8d9acff" xlink:to="loc_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_f8f94999-bc96-4c41-8585-4c37eeaf2ee3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanActualReturnOnPlanAssets_726b1573-4484-4f45-a5fe-0b47441a151f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanActualReturnOnPlanAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward_edfbed3e-fcd9-4a89-97cd-f5d2c8d9acff" xlink:to="loc_us-gaap_DefinedBenefitPlanActualReturnOnPlanAssets_726b1573-4484-4f45-a5fe-0b47441a151f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanContributionsByEmployer_494e0e88-f160-4133-b65f-8a11d24a8c57" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanContributionsByEmployer"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward_edfbed3e-fcd9-4a89-97cd-f5d2c8d9acff" xlink:to="loc_us-gaap_DefinedBenefitPlanContributionsByEmployer_494e0e88-f160-4133-b65f-8a11d24a8c57" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanPlanAssetsContributionsByPlanParticipant_c352dd2d-7514-46c9-9659-dc647fd3c6f3" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanPlanAssetsContributionsByPlanParticipant"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward_edfbed3e-fcd9-4a89-97cd-f5d2c8d9acff" xlink:to="loc_us-gaap_DefinedBenefitPlanPlanAssetsContributionsByPlanParticipant_c352dd2d-7514-46c9-9659-dc647fd3c6f3" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanPlanAssetsBenefitsPaid_688d3f14-c629-4f9e-9de4-b91b435f6f0e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanPlanAssetsBenefitsPaid"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward_edfbed3e-fcd9-4a89-97cd-f5d2c8d9acff" xlink:to="loc_us-gaap_DefinedBenefitPlanPlanAssetsBenefitsPaid_688d3f14-c629-4f9e-9de4-b91b435f6f0e" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_DefinedBenefitPlanPlanAssetsPaymentForSettlementAndOther_580d6445-5320-4de6-8235-fe14221c8bbd" xlink:href="wab-20211231.xsd#wab_DefinedBenefitPlanPlanAssetsPaymentForSettlementAndOther"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward_edfbed3e-fcd9-4a89-97cd-f5d2c8d9acff" xlink:to="loc_wab_DefinedBenefitPlanPlanAssetsPaymentForSettlementAndOther_580d6445-5320-4de6-8235-fe14221c8bbd" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanPlanAssetsForeignCurrencyTranslationGainLoss_a3921355-d11f-44ab-9173-fb4db378434c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanPlanAssetsForeignCurrencyTranslationGainLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanChangeInFairValueOfPlanAssetsRollForward_edfbed3e-fcd9-4a89-97cd-f5d2c8d9acff" xlink:to="loc_us-gaap_DefinedBenefitPlanPlanAssetsForeignCurrencyTranslationGainLoss_a3921355-d11f-44ab-9173-fb4db378434c" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_f84d6135-8c7f-4f7f-9826-d4df75c06119" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanFairValueOfPlanAssets"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_11de1c7f-991f-4f1f-aaf7-a8ca4f989c24" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanFairValueOfPlanAssets"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanBenefitObligation_5eb4b515-2880-4edb-bf52-aa9309aa0565" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanBenefitObligation"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanFundedStatusOfPlan_cd72bac6-5623-43ff-af23-d7cfcfd1e413" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanFundedStatusOfPlan"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_c657e43e-06ec-4f3e-9844-2bfaea302bb6" xlink:to="loc_us-gaap_DefinedBenefitPlanFundedStatusOfPlan_cd72bac6-5623-43ff-af23-d7cfcfd1e413" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAmountsRecognizedInBalanceSheetAbstract_23688846-10ec-4163-8b83-dfeba89cad47" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanAmountsRecognizedInBalanceSheetAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_c657e43e-06ec-4f3e-9844-2bfaea302bb6" xlink:to="loc_us-gaap_DefinedBenefitPlanAmountsRecognizedInBalanceSheetAbstract_23688846-10ec-4163-8b83-dfeba89cad47" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAssetsForPlanBenefitsNoncurrent_1c93dd81-8160-4813-81af-0fbad27c563d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanAssetsForPlanBenefitsNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanAmountsRecognizedInBalanceSheetAbstract_23688846-10ec-4163-8b83-dfeba89cad47" xlink:to="loc_us-gaap_DefinedBenefitPlanAssetsForPlanBenefitsNoncurrent_1c93dd81-8160-4813-81af-0fbad27c563d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansCurrentLiabilities_c70dea45-49d8-4a67-aead-535e11696f77" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansCurrentLiabilities"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanAmountsRecognizedInBalanceSheetAbstract_23688846-10ec-4163-8b83-dfeba89cad47" xlink:to="loc_us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansCurrentLiabilities_c70dea45-49d8-4a67-aead-535e11696f77" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent_1785d5ec-7e27-4f42-868b-a45efea1461f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanAmountsRecognizedInBalanceSheetAbstract_23688846-10ec-4163-8b83-dfeba89cad47" xlink:to="loc_us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent_1785d5ec-7e27-4f42-868b-a45efea1461f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAmountsRecognizedInBalanceSheet_270dca4c-ac3b-4980-8651-791ab5f3976c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanAmountsRecognizedInBalanceSheet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanAmountsRecognizedInBalanceSheetAbstract_23688846-10ec-4163-8b83-dfeba89cad47" xlink:to="loc_us-gaap_DefinedBenefitPlanAmountsRecognizedInBalanceSheet_270dca4c-ac3b-4980-8651-791ab5f3976c" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAmountsRecognizedInOtherComprehensiveIncomeAbstract_043f6f77-2813-4e21-9b2e-85fd63e02183" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanAmountsRecognizedInOtherComprehensiveIncomeAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_c657e43e-06ec-4f3e-9844-2bfaea302bb6" xlink:to="loc_us-gaap_DefinedBenefitPlanAmountsRecognizedInOtherComprehensiveIncomeAbstract_043f6f77-2813-4e21-9b2e-85fd63e02183" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetPriorServiceCostCreditBeforeTax_e29c971a-a6c9-4b40-bad0-25b20a72bf62" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetPriorServiceCostCreditBeforeTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanAmountsRecognizedInOtherComprehensiveIncomeAbstract_043f6f77-2813-4e21-9b2e-85fd63e02183" xlink:to="loc_us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetPriorServiceCostCreditBeforeTax_e29c971a-a6c9-4b40-bad0-25b20a72bf62" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesBeforeTax_7f37c149-483c-45d3-aeca-faeef72657a0" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesBeforeTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanAmountsRecognizedInOtherComprehensiveIncomeAbstract_043f6f77-2813-4e21-9b2e-85fd63e02183" xlink:to="loc_us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeNetGainsLossesBeforeTax_7f37c149-483c-45d3-aeca-faeef72657a0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeBeforeTax_c06fe267-2475-44c5-b72b-347fa1190de3" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeBeforeTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanAmountsRecognizedInOtherComprehensiveIncomeAbstract_043f6f77-2813-4e21-9b2e-85fd63e02183" xlink:to="loc_us-gaap_DefinedBenefitPlanAccumulatedOtherComprehensiveIncomeBeforeTax_c06fe267-2475-44c5-b72b-347fa1190de3" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_a51b5f81-aa58-4328-b750-e7e1c6d510e4" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_c657e43e-06ec-4f3e-9844-2bfaea302bb6" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_a51b5f81-aa58-4328-b750-e7e1c6d510e4" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationAxis_ba6692e1-f269-4a46-b619-a9c58ad8ba1e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetirementPlanSponsorLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_a51b5f81-aa58-4328-b750-e7e1c6d510e4" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationAxis_ba6692e1-f269-4a46-b619-a9c58ad8ba1e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_ba6692e1-f269-4a46-b619-a9c58ad8ba1e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_ba6692e1-f269-4a46-b619-a9c58ad8ba1e" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_ba6692e1-f269-4a46-b619-a9c58ad8ba1e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_6db312c3-6009-45f4-91cf-b72d955c02c1" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_ba6692e1-f269-4a46-b619-a9c58ad8ba1e" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_6db312c3-6009-45f4-91cf-b72d955c02c1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DomesticPlanMember_4b477dfe-6cc6-4b97-9616-3a9455c5f447" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DomesticPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_6db312c3-6009-45f4-91cf-b72d955c02c1" xlink:to="loc_us-gaap_DomesticPlanMember_4b477dfe-6cc6-4b97-9616-3a9455c5f447" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_US_4888196b-505c-42d8-a020-503babff8086" xlink:href="https://xbrl.sec.gov/country/2021/country-2021.xsd#country_US"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DomesticPlanMember_4b477dfe-6cc6-4b97-9616-3a9455c5f447" xlink:to="loc_country_US_4888196b-505c-42d8-a020-503babff8086" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignPlanMember_ee1d7ba5-21d2-4698-84b1-4b90a5ebd62d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ForeignPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_6db312c3-6009-45f4-91cf-b72d955c02c1" xlink:to="loc_us-gaap_ForeignPlanMember_ee1d7ba5-21d2-4698-84b1-4b90a5ebd62d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_b3e5d0e6-0d7d-4399-b7ff-259ca9cb2d6a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetirementPlanTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_a51b5f81-aa58-4328-b750-e7e1c6d510e4" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_b3e5d0e6-0d7d-4399-b7ff-259ca9cb2d6a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_b3e5d0e6-0d7d-4399-b7ff-259ca9cb2d6a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_b3e5d0e6-0d7d-4399-b7ff-259ca9cb2d6a" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_b3e5d0e6-0d7d-4399-b7ff-259ca9cb2d6a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_85b8a453-c3ed-4338-8b33-20363e6b2f1f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_b3e5d0e6-0d7d-4399-b7ff-259ca9cb2d6a" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_85b8a453-c3ed-4338-8b33-20363e6b2f1f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionPlansDefinedBenefitMember_5ca82bca-366b-4e47-90fc-02e7c3c26bc1" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PensionPlansDefinedBenefitMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_85b8a453-c3ed-4338-8b33-20363e6b2f1f" xlink:to="loc_us-gaap_PensionPlansDefinedBenefitMember_5ca82bca-366b-4e47-90fc-02e7c3c26bc1" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/EMPLOYEEBENEFITPLANSNarrativeDetails" xlink:type="simple" xlink:href="wab-20211231.xsd#EMPLOYEEBENEFITPLANSNarrativeDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/EMPLOYEEBENEFITPLANSNarrativeDetails" xlink:type="extended" id="i33675f273b39435b923408b54c76935b_EMPLOYEEBENEFITPLANSNarrativeDetails">
    <link:loc xlink:type="locator" xlink:label="loc_wab_DefinedBenefitPlansAndOtherPostretirementBenefitPlansLineItems_2f8f5749-8848-46c2-acb1-57e53cb1c4b8" xlink:href="wab-20211231.xsd#wab_DefinedBenefitPlansAndOtherPostretirementBenefitPlansLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAccumulatedBenefitObligation_f3672882-6caa-45fe-be40-b1b52fd774bc" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanAccumulatedBenefitObligation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_wab_DefinedBenefitPlansAndOtherPostretirementBenefitPlansLineItems_2f8f5749-8848-46c2-acb1-57e53cb1c4b8" xlink:to="loc_us-gaap_DefinedBenefitPlanAccumulatedBenefitObligation_f3672882-6caa-45fe-be40-b1b52fd774bc" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanPlanAssetsTargetAllocationPercentage_9854564b-2475-4424-a102-40a42037d013" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanPlanAssetsTargetAllocationPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_wab_DefinedBenefitPlansAndOtherPostretirementBenefitPlansLineItems_2f8f5749-8848-46c2-acb1-57e53cb1c4b8" xlink:to="loc_us-gaap_DefinedBenefitPlanPlanAssetsTargetAllocationPercentage_9854564b-2475-4424-a102-40a42037d013" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedFutureEmployerContributionsNextFiscalYear_f74c7936-32f5-4c79-9e51-1e41148e566a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedFutureEmployerContributionsNextFiscalYear"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_wab_DefinedBenefitPlansAndOtherPostretirementBenefitPlansLineItems_2f8f5749-8848-46c2-acb1-57e53cb1c4b8" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedFutureEmployerContributionsNextFiscalYear_f74c7936-32f5-4c79-9e51-1e41148e566a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedContributionPlanCostRecognized_e3590dd6-a1f9-4fda-ac35-0578f3f03573" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedContributionPlanCostRecognized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_wab_DefinedBenefitPlansAndOtherPostretirementBenefitPlansLineItems_2f8f5749-8848-46c2-acb1-57e53cb1c4b8" xlink:to="loc_us-gaap_DefinedContributionPlanCostRecognized_e3590dd6-a1f9-4fda-ac35-0578f3f03573" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_DefinedContributionPlanNumberOfSharesHeldOnBehalfOfParticipants_048afc20-30b2-4b72-b14f-7b08f5960689" xlink:href="wab-20211231.xsd#wab_DefinedContributionPlanNumberOfSharesHeldOnBehalfOfParticipants"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_wab_DefinedBenefitPlansAndOtherPostretirementBenefitPlansLineItems_2f8f5749-8848-46c2-acb1-57e53cb1c4b8" xlink:to="loc_wab_DefinedContributionPlanNumberOfSharesHeldOnBehalfOfParticipants_048afc20-30b2-4b72-b14f-7b08f5960689" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_DefinedContributionPlanMarketValueOfSharesHeldOnBehalfOfParticipants_435f8deb-3c80-4f63-8eca-e0d1531c741f" xlink:href="wab-20211231.xsd#wab_DefinedContributionPlanMarketValueOfSharesHeldOnBehalfOfParticipants"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_wab_DefinedBenefitPlansAndOtherPostretirementBenefitPlansLineItems_2f8f5749-8848-46c2-acb1-57e53cb1c4b8" xlink:to="loc_wab_DefinedContributionPlanMarketValueOfSharesHeldOnBehalfOfParticipants_435f8deb-3c80-4f63-8eca-e0d1531c741f" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTable_d1de40c4-7566-493b-91bf-85373ad3e18f" xlink:href="wab-20211231.xsd#wab_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_wab_DefinedBenefitPlansAndOtherPostretirementBenefitPlansLineItems_2f8f5749-8848-46c2-acb1-57e53cb1c4b8" xlink:to="loc_wab_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTable_d1de40c4-7566-493b-91bf-85373ad3e18f" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationAxis_a14eef44-4cd2-4f1c-b1cb-79d51488a5ed" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetirementPlanSponsorLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_wab_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTable_d1de40c4-7566-493b-91bf-85373ad3e18f" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationAxis_a14eef44-4cd2-4f1c-b1cb-79d51488a5ed" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_a14eef44-4cd2-4f1c-b1cb-79d51488a5ed_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_a14eef44-4cd2-4f1c-b1cb-79d51488a5ed" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_a14eef44-4cd2-4f1c-b1cb-79d51488a5ed_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_3d159ab4-ce87-4c93-9547-b160d15adb16" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_a14eef44-4cd2-4f1c-b1cb-79d51488a5ed" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_3d159ab4-ce87-4c93-9547-b160d15adb16" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DomesticPlanMember_7403ac17-aaaf-4ee7-9338-a9008b3cd0e7" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DomesticPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_3d159ab4-ce87-4c93-9547-b160d15adb16" xlink:to="loc_us-gaap_DomesticPlanMember_7403ac17-aaaf-4ee7-9338-a9008b3cd0e7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_US_e96b3f3a-e7c4-4e8a-9840-69cffdc599a3" xlink:href="https://xbrl.sec.gov/country/2021/country-2021.xsd#country_US"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DomesticPlanMember_7403ac17-aaaf-4ee7-9338-a9008b3cd0e7" xlink:to="loc_country_US_e96b3f3a-e7c4-4e8a-9840-69cffdc599a3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignPlanMember_fd686968-59db-4d0f-b9a3-3376debfce74" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ForeignPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_3d159ab4-ce87-4c93-9547-b160d15adb16" xlink:to="loc_us-gaap_ForeignPlanMember_fd686968-59db-4d0f-b9a3-3376debfce74" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_28e8c1ca-7d7d-4328-9836-28f89aa3bc20" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetirementPlanTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_wab_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTable_d1de40c4-7566-493b-91bf-85373ad3e18f" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_28e8c1ca-7d7d-4328-9836-28f89aa3bc20" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_28e8c1ca-7d7d-4328-9836-28f89aa3bc20_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_28e8c1ca-7d7d-4328-9836-28f89aa3bc20" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_28e8c1ca-7d7d-4328-9836-28f89aa3bc20_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_23ab71f4-9260-4135-826c-cfce45e9258b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_28e8c1ca-7d7d-4328-9836-28f89aa3bc20" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_23ab71f4-9260-4135-826c-cfce45e9258b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionPlansDefinedBenefitMember_fa63a762-975b-43ba-8131-e99a6483c155" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PensionPlansDefinedBenefitMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_23ab71f4-9260-4135-826c-cfce45e9258b" xlink:to="loc_us-gaap_PensionPlansDefinedBenefitMember_fa63a762-975b-43ba-8131-e99a6483c155" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_e23de0b3-7eaa-4f7b-a2e0-de75be876f43" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_wab_DefinedBenefitPlansAndOtherPostretirementBenefitPlansTable_d1de40c4-7566-493b-91bf-85373ad3e18f" xlink:to="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_e23de0b3-7eaa-4f7b-a2e0-de75be876f43" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanAssetCategoriesDomain_e23de0b3-7eaa-4f7b-a2e0-de75be876f43_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PlanAssetCategoriesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_e23de0b3-7eaa-4f7b-a2e0-de75be876f43" xlink:to="loc_us-gaap_PlanAssetCategoriesDomain_e23de0b3-7eaa-4f7b-a2e0-de75be876f43_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanAssetCategoriesDomain_f7be021f-7529-4bc1-a9bf-d5bfb39874cf" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PlanAssetCategoriesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_e23de0b3-7eaa-4f7b-a2e0-de75be876f43" xlink:to="loc_us-gaap_PlanAssetCategoriesDomain_f7be021f-7529-4bc1-a9bf-d5bfb39874cf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanEquitySecuritiesMember_fc874c55-edb0-4f49-9657-8fb28c2537f6" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanEquitySecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_f7be021f-7529-4bc1-a9bf-d5bfb39874cf" xlink:to="loc_us-gaap_DefinedBenefitPlanEquitySecuritiesMember_fc874c55-edb0-4f49-9657-8fb28c2537f6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanDebtSecurityMember_3f336600-26ed-46f8-8ec8-af3ea55303dd" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanDebtSecurityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_f7be021f-7529-4bc1-a9bf-d5bfb39874cf" xlink:to="loc_us-gaap_DefinedBenefitPlanDebtSecurityMember_3f336600-26ed-46f8-8ec8-af3ea55303dd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherInvestmentsMember_e9a6cb8f-c5aa-42ad-a827-4a69fc952bb4" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherInvestmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_f7be021f-7529-4bc1-a9bf-d5bfb39874cf" xlink:to="loc_us-gaap_OtherInvestmentsMember_e9a6cb8f-c5aa-42ad-a827-4a69fc952bb4" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/EMPLOYEEBENEFITPLANSScheduleofUSandInternationalPensionPlanswithAccumulatedBenefitObligationsandwithProjectedBenefitObligationsinExcessofPlanAssetsDetails" xlink:type="simple" xlink:href="wab-20211231.xsd#EMPLOYEEBENEFITPLANSScheduleofUSandInternationalPensionPlanswithAccumulatedBenefitObligationsandwithProjectedBenefitObligationsinExcessofPlanAssetsDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/EMPLOYEEBENEFITPLANSScheduleofUSandInternationalPensionPlanswithAccumulatedBenefitObligationsandwithProjectedBenefitObligationsinExcessofPlanAssetsDetails" xlink:type="extended" id="i5b21fa298ba34858a37e13202221913c_EMPLOYEEBENEFITPLANSScheduleofUSandInternationalPensionPlanswithAccumulatedBenefitObligationsandwithProjectedBenefitObligationsinExcessofPlanAssetsDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_c7350a26-0503-486d-bda4-614b9c02af05" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAbstract_2985d476-7a76-4b7c-8c85-8bbbc3f82aef" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_c7350a26-0503-486d-bda4-614b9c02af05" xlink:to="loc_us-gaap_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAbstract_2985d476-7a76-4b7c-8c85-8bbbc3f82aef" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateProjectedBenefitObligation_8db26c9f-ccbc-4ae3-9b71-d3d7b55b6b35" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateProjectedBenefitObligation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAbstract_2985d476-7a76-4b7c-8c85-8bbbc3f82aef" xlink:to="loc_us-gaap_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateProjectedBenefitObligation_8db26c9f-ccbc-4ae3-9b71-d3d7b55b6b35" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateAccumulatedBenefitObligation_ea581f08-755a-4a9b-a1d3-d546eab9e6fb" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateAccumulatedBenefitObligation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAbstract_2985d476-7a76-4b7c-8c85-8bbbc3f82aef" xlink:to="loc_us-gaap_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateAccumulatedBenefitObligation_ea581f08-755a-4a9b-a1d3-d546eab9e6fb" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateFairValueOfPlanAssets_20f8a130-ecd6-450d-8f3f-8b600c2fa7bc" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateFairValueOfPlanAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAbstract_2985d476-7a76-4b7c-8c85-8bbbc3f82aef" xlink:to="loc_us-gaap_DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateFairValueOfPlanAssets_20f8a130-ecd6-450d-8f3f-8b600c2fa7bc" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanPlansWithBenefitObligationsInExcessOfPlanAssetsAbstract_603db1a5-819e-4eb4-b40b-6ed477a1f925" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanPlansWithBenefitObligationsInExcessOfPlanAssetsAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_c7350a26-0503-486d-bda4-614b9c02af05" xlink:to="loc_us-gaap_DefinedBenefitPlanPlansWithBenefitObligationsInExcessOfPlanAssetsAbstract_603db1a5-819e-4eb4-b40b-6ed477a1f925" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanPensionPlanWithProjectedBenefitObligationInExcessOfPlanAssetsProjectedBenefitObligation_69ffc570-427e-4199-be42-983d9fd10210" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanPensionPlanWithProjectedBenefitObligationInExcessOfPlanAssetsProjectedBenefitObligation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanPlansWithBenefitObligationsInExcessOfPlanAssetsAbstract_603db1a5-819e-4eb4-b40b-6ed477a1f925" xlink:to="loc_us-gaap_DefinedBenefitPlanPensionPlanWithProjectedBenefitObligationInExcessOfPlanAssetsProjectedBenefitObligation_69ffc570-427e-4199-be42-983d9fd10210" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanPensionPlanWithProjectedBenefitObligationInExcessOfPlanAssetsAccumulatedBenefitObligation_cc7b0513-72fa-4c83-8490-18c8065b0962" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanPensionPlanWithProjectedBenefitObligationInExcessOfPlanAssetsAccumulatedBenefitObligation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanPlansWithBenefitObligationsInExcessOfPlanAssetsAbstract_603db1a5-819e-4eb4-b40b-6ed477a1f925" xlink:to="loc_us-gaap_DefinedBenefitPlanPensionPlanWithProjectedBenefitObligationInExcessOfPlanAssetsAccumulatedBenefitObligation_cc7b0513-72fa-4c83-8490-18c8065b0962" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanPensionPlanWithProjectedBenefitObligationInExcessOfPlanAssetsPlanAssets_ee8e00a4-0d4f-444a-8ba7-17d5d9b60149" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanPensionPlanWithProjectedBenefitObligationInExcessOfPlanAssetsPlanAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanPlansWithBenefitObligationsInExcessOfPlanAssetsAbstract_603db1a5-819e-4eb4-b40b-6ed477a1f925" xlink:to="loc_us-gaap_DefinedBenefitPlanPensionPlanWithProjectedBenefitObligationInExcessOfPlanAssetsPlanAssets_ee8e00a4-0d4f-444a-8ba7-17d5d9b60149" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_2297b3a7-24f8-49a1-b6af-b78e5968e558" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_c7350a26-0503-486d-bda4-614b9c02af05" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_2297b3a7-24f8-49a1-b6af-b78e5968e558" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationAxis_9c22dcda-5527-452e-918c-cf7f312de29c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetirementPlanSponsorLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_2297b3a7-24f8-49a1-b6af-b78e5968e558" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationAxis_9c22dcda-5527-452e-918c-cf7f312de29c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_9c22dcda-5527-452e-918c-cf7f312de29c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_9c22dcda-5527-452e-918c-cf7f312de29c" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_9c22dcda-5527-452e-918c-cf7f312de29c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_ab849ba1-e960-436c-862a-2bd46f75e8a9" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_9c22dcda-5527-452e-918c-cf7f312de29c" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_ab849ba1-e960-436c-862a-2bd46f75e8a9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DomesticPlanMember_1f35163d-be42-4a5f-a4a3-e3904ca8fa10" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DomesticPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_ab849ba1-e960-436c-862a-2bd46f75e8a9" xlink:to="loc_us-gaap_DomesticPlanMember_1f35163d-be42-4a5f-a4a3-e3904ca8fa10" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_US_1156d6cb-c8d5-4bd0-a89e-6c84c102c253" xlink:href="https://xbrl.sec.gov/country/2021/country-2021.xsd#country_US"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DomesticPlanMember_1f35163d-be42-4a5f-a4a3-e3904ca8fa10" xlink:to="loc_country_US_1156d6cb-c8d5-4bd0-a89e-6c84c102c253" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignPlanMember_baa25b90-4121-4a61-8f08-c04e97051f16" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ForeignPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_ab849ba1-e960-436c-862a-2bd46f75e8a9" xlink:to="loc_us-gaap_ForeignPlanMember_baa25b90-4121-4a61-8f08-c04e97051f16" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_a7b885f8-37d9-498e-847b-515d04f41ccf" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetirementPlanTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_2297b3a7-24f8-49a1-b6af-b78e5968e558" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_a7b885f8-37d9-498e-847b-515d04f41ccf" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_a7b885f8-37d9-498e-847b-515d04f41ccf_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_a7b885f8-37d9-498e-847b-515d04f41ccf" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_a7b885f8-37d9-498e-847b-515d04f41ccf_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_bc0a1d5f-fbff-47a5-a7dc-4ed112821825" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_a7b885f8-37d9-498e-847b-515d04f41ccf" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_bc0a1d5f-fbff-47a5-a7dc-4ed112821825" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionPlansDefinedBenefitMember_41b4e56a-3c68-4dee-87eb-6512944f5dfb" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PensionPlansDefinedBenefitMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_bc0a1d5f-fbff-47a5-a7dc-4ed112821825" xlink:to="loc_us-gaap_PensionPlansDefinedBenefitMember_41b4e56a-3c68-4dee-87eb-6512944f5dfb" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/EMPLOYEEBENEFITPLANSComponentsofNetPeriodicBenefitCostsDetails" xlink:type="simple" xlink:href="wab-20211231.xsd#EMPLOYEEBENEFITPLANSComponentsofNetPeriodicBenefitCostsDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/EMPLOYEEBENEFITPLANSComponentsofNetPeriodicBenefitCostsDetails" xlink:type="extended" id="i6fc0e19101fa492488f75e29e40edace_EMPLOYEEBENEFITPLANSComponentsofNetPeriodicBenefitCostsDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_a6b8d290-44c9-472b-80f7-0e48a2ca2439" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanServiceCost_c21783c6-46ad-4a7a-9400-8dda3099dfca" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanServiceCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_a6b8d290-44c9-472b-80f7-0e48a2ca2439" xlink:to="loc_us-gaap_DefinedBenefitPlanServiceCost_c21783c6-46ad-4a7a-9400-8dda3099dfca" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanInterestCost_a8f39e85-0b9d-4b88-a567-847390c87f88" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanInterestCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_a6b8d290-44c9-472b-80f7-0e48a2ca2439" xlink:to="loc_us-gaap_DefinedBenefitPlanInterestCost_a8f39e85-0b9d-4b88-a567-847390c87f88" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets_2fd03184-d997-43df-a343-35b148f8c722" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_a6b8d290-44c9-472b-80f7-0e48a2ca2439" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets_2fd03184-d997-43df-a343-35b148f8c722" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses_ee8489e2-6058-40fc-9db6-db496e99ba67" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_a6b8d290-44c9-472b-80f7-0e48a2ca2439" xlink:to="loc_us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses_ee8489e2-6058-40fc-9db6-db496e99ba67" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanRecognizedNetGainLossDueToSettlementsAndCurtailments1_4fc63ffe-4be7-41c7-99f3-3b5ee512886d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanRecognizedNetGainLossDueToSettlementsAndCurtailments1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_a6b8d290-44c9-472b-80f7-0e48a2ca2439" xlink:to="loc_us-gaap_DefinedBenefitPlanRecognizedNetGainLossDueToSettlementsAndCurtailments1_4fc63ffe-4be7-41c7-99f3-3b5ee512886d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost_bceb4723-84f5-4a2c-8740-6a1b08926f5b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_a6b8d290-44c9-472b-80f7-0e48a2ca2439" xlink:to="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost_bceb4723-84f5-4a2c-8740-6a1b08926f5b" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_8dc4ef59-ebe2-424b-b3f5-8fc78efff2ed" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_a6b8d290-44c9-472b-80f7-0e48a2ca2439" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_8dc4ef59-ebe2-424b-b3f5-8fc78efff2ed" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationAxis_4bcdd7d5-2237-4f4d-9f5b-ba217380b741" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetirementPlanSponsorLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_8dc4ef59-ebe2-424b-b3f5-8fc78efff2ed" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationAxis_4bcdd7d5-2237-4f4d-9f5b-ba217380b741" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_4bcdd7d5-2237-4f4d-9f5b-ba217380b741_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_4bcdd7d5-2237-4f4d-9f5b-ba217380b741" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_4bcdd7d5-2237-4f4d-9f5b-ba217380b741_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_97f1bfff-a772-48e9-9374-d0ad44a8fb08" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_4bcdd7d5-2237-4f4d-9f5b-ba217380b741" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_97f1bfff-a772-48e9-9374-d0ad44a8fb08" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DomesticPlanMember_21150cf6-8355-4e93-b801-38dae2c56634" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DomesticPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_97f1bfff-a772-48e9-9374-d0ad44a8fb08" xlink:to="loc_us-gaap_DomesticPlanMember_21150cf6-8355-4e93-b801-38dae2c56634" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_US_5102d11f-b925-4f1c-84c3-4d422e770068" xlink:href="https://xbrl.sec.gov/country/2021/country-2021.xsd#country_US"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DomesticPlanMember_21150cf6-8355-4e93-b801-38dae2c56634" xlink:to="loc_country_US_5102d11f-b925-4f1c-84c3-4d422e770068" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignPlanMember_80950719-a981-4e02-ad1e-59e038e75e5b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ForeignPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_97f1bfff-a772-48e9-9374-d0ad44a8fb08" xlink:to="loc_us-gaap_ForeignPlanMember_80950719-a981-4e02-ad1e-59e038e75e5b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_d799163d-9e2c-415a-8152-0fa5e169c65d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetirementPlanTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_8dc4ef59-ebe2-424b-b3f5-8fc78efff2ed" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_d799163d-9e2c-415a-8152-0fa5e169c65d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_d799163d-9e2c-415a-8152-0fa5e169c65d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_d799163d-9e2c-415a-8152-0fa5e169c65d" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_d799163d-9e2c-415a-8152-0fa5e169c65d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_8b70fc93-1d60-4c91-b422-27a693eaba46" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_d799163d-9e2c-415a-8152-0fa5e169c65d" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_8b70fc93-1d60-4c91-b422-27a693eaba46" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionPlansDefinedBenefitMember_871adc2c-dc7c-4163-8547-92b18ad56b86" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PensionPlansDefinedBenefitMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_8b70fc93-1d60-4c91-b422-27a693eaba46" xlink:to="loc_us-gaap_PensionPlansDefinedBenefitMember_871adc2c-dc7c-4163-8547-92b18ad56b86" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/EMPLOYEEBENEFITPLANSOtherChangesinPlanAssetsandBenefitObligationsRecognizedinOtherComprehensiveIncomeDetails" xlink:type="simple" xlink:href="wab-20211231.xsd#EMPLOYEEBENEFITPLANSOtherChangesinPlanAssetsandBenefitObligationsRecognizedinOtherComprehensiveIncomeDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/EMPLOYEEBENEFITPLANSOtherChangesinPlanAssetsandBenefitObligationsRecognizedinOtherComprehensiveIncomeDetails" xlink:type="extended" id="ic0f28a77ed794ef1b97f90f137049752_EMPLOYEEBENEFITPLANSOtherChangesinPlanAssetsandBenefitObligationsRecognizedinOtherComprehensiveIncomeDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_285e99a0-465a-4694-a080-21f155d6b1cf" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossNetOfTax_8bdf8ce6-e448-4e43-81c8-13050c05ff3b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_285e99a0-465a-4694-a080-21f155d6b1cf" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossReclassificationAdjustmentFromAOCIPensionAndOtherPostretirementBenefitPlansForNetGainLossNetOfTax_8bdf8ce6-e448-4e43-81c8-13050c05ff3b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_OtherComprehensiveIncomeDefinedBenefitPlansEffectOfExchangeRates_7ab5832e-8688-431b-ac52-91f118441326" xlink:href="wab-20211231.xsd#wab_OtherComprehensiveIncomeDefinedBenefitPlansEffectOfExchangeRates"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_285e99a0-465a-4694-a080-21f155d6b1cf" xlink:to="loc_wab_OtherComprehensiveIncomeDefinedBenefitPlansEffectOfExchangeRates_7ab5832e-8688-431b-ac52-91f118441326" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAmountsRecognizedInOtherComprehensiveIncomeLossNetGainLossBeforeTax_16a391b2-25eb-4680-a35b-d2ba167c902b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanAmountsRecognizedInOtherComprehensiveIncomeLossNetGainLossBeforeTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_285e99a0-465a-4694-a080-21f155d6b1cf" xlink:to="loc_us-gaap_DefinedBenefitPlanAmountsRecognizedInOtherComprehensiveIncomeLossNetGainLossBeforeTax_16a391b2-25eb-4680-a35b-d2ba167c902b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeDefinedBenefitPlansAdjustmentNetOfTaxPortionAttributableToParent_4ad05b07-0c01-4f40-bcf7-aa4bbf0d0574" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherComprehensiveIncomeDefinedBenefitPlansAdjustmentNetOfTaxPortionAttributableToParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_285e99a0-465a-4694-a080-21f155d6b1cf" xlink:to="loc_us-gaap_OtherComprehensiveIncomeDefinedBenefitPlansAdjustmentNetOfTaxPortionAttributableToParent_4ad05b07-0c01-4f40-bcf7-aa4bbf0d0574" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_4e5338af-1d95-4510-a125-a06a8078c125" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_285e99a0-465a-4694-a080-21f155d6b1cf" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_4e5338af-1d95-4510-a125-a06a8078c125" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationAxis_43aeb1d4-e50b-4f0d-ac6b-a96602f0aa3f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetirementPlanSponsorLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_4e5338af-1d95-4510-a125-a06a8078c125" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationAxis_43aeb1d4-e50b-4f0d-ac6b-a96602f0aa3f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_43aeb1d4-e50b-4f0d-ac6b-a96602f0aa3f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_43aeb1d4-e50b-4f0d-ac6b-a96602f0aa3f" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_43aeb1d4-e50b-4f0d-ac6b-a96602f0aa3f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_559b9444-d057-4c19-a610-887c58c8338b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_43aeb1d4-e50b-4f0d-ac6b-a96602f0aa3f" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_559b9444-d057-4c19-a610-887c58c8338b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DomesticPlanMember_3e8f4294-1149-4474-8c3d-e1d2763c3b9e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DomesticPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_559b9444-d057-4c19-a610-887c58c8338b" xlink:to="loc_us-gaap_DomesticPlanMember_3e8f4294-1149-4474-8c3d-e1d2763c3b9e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_US_d5db0e8e-21a8-4215-a98d-b41444e5edfb" xlink:href="https://xbrl.sec.gov/country/2021/country-2021.xsd#country_US"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DomesticPlanMember_3e8f4294-1149-4474-8c3d-e1d2763c3b9e" xlink:to="loc_country_US_d5db0e8e-21a8-4215-a98d-b41444e5edfb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignPlanMember_831b2c7b-3b50-4602-9af4-8f44b13a4746" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ForeignPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_559b9444-d057-4c19-a610-887c58c8338b" xlink:to="loc_us-gaap_ForeignPlanMember_831b2c7b-3b50-4602-9af4-8f44b13a4746" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_2967af82-6ad5-45f9-81ca-4aa3a9c95617" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetirementPlanTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_4e5338af-1d95-4510-a125-a06a8078c125" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_2967af82-6ad5-45f9-81ca-4aa3a9c95617" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_2967af82-6ad5-45f9-81ca-4aa3a9c95617_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_2967af82-6ad5-45f9-81ca-4aa3a9c95617" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_2967af82-6ad5-45f9-81ca-4aa3a9c95617_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_33af4210-c7f7-42b0-93cc-12f98f0b98ac" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_2967af82-6ad5-45f9-81ca-4aa3a9c95617" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_33af4210-c7f7-42b0-93cc-12f98f0b98ac" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionPlansDefinedBenefitMember_6c14d86f-1cd4-49fe-8fd6-605ff848d80f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PensionPlansDefinedBenefitMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_33af4210-c7f7-42b0-93cc-12f98f0b98ac" xlink:to="loc_us-gaap_PensionPlansDefinedBenefitMember_6c14d86f-1cd4-49fe-8fd6-605ff848d80f" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/EMPLOYEEBENEFITPLANSWeightedAverageAssumptionsUsedtoDevelopActuarialPresentValueofProjectedBenefitObligationDetails" xlink:type="simple" xlink:href="wab-20211231.xsd#EMPLOYEEBENEFITPLANSWeightedAverageAssumptionsUsedtoDevelopActuarialPresentValueofProjectedBenefitObligationDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/EMPLOYEEBENEFITPLANSWeightedAverageAssumptionsUsedtoDevelopActuarialPresentValueofProjectedBenefitObligationDetails" xlink:type="extended" id="i31733ef33c354bf69389b0b26685ffb6_EMPLOYEEBENEFITPLANSWeightedAverageAssumptionsUsedtoDevelopActuarialPresentValueofProjectedBenefitObligationDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_f520660a-9556-4eeb-8a07-0e008ae66192" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate_bb5bb5ee-06ad-4490-aa96-59a702d48b89" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_f520660a-9556-4eeb-8a07-0e008ae66192" xlink:to="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostDiscountRate_bb5bb5ee-06ad-4490-aa96-59a702d48b89" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostExpectedLongTermReturnOnAssets_c8059de4-1949-4a6a-8133-4292101d591e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostExpectedLongTermReturnOnAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_f520660a-9556-4eeb-8a07-0e008ae66192" xlink:to="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostExpectedLongTermReturnOnAssets_c8059de4-1949-4a6a-8133-4292101d591e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostRateOfCompensationIncrease_2ae94df4-baa3-4911-943c-74350d1c6243" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostRateOfCompensationIncrease"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_f520660a-9556-4eeb-8a07-0e008ae66192" xlink:to="loc_us-gaap_DefinedBenefitPlanAssumptionsUsedCalculatingNetPeriodicBenefitCostRateOfCompensationIncrease_2ae94df4-baa3-4911-943c-74350d1c6243" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_dc9498ea-3068-40c9-baf8-720fd5fc2f0a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_f520660a-9556-4eeb-8a07-0e008ae66192" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_dc9498ea-3068-40c9-baf8-720fd5fc2f0a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationAxis_cc9b1d10-ae57-419b-a107-8ecd8266eeb8" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetirementPlanSponsorLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_dc9498ea-3068-40c9-baf8-720fd5fc2f0a" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationAxis_cc9b1d10-ae57-419b-a107-8ecd8266eeb8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_cc9b1d10-ae57-419b-a107-8ecd8266eeb8_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_cc9b1d10-ae57-419b-a107-8ecd8266eeb8" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_cc9b1d10-ae57-419b-a107-8ecd8266eeb8_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_de061e24-50a0-4d03-8bf8-38dca02275a7" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_cc9b1d10-ae57-419b-a107-8ecd8266eeb8" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_de061e24-50a0-4d03-8bf8-38dca02275a7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DomesticPlanMember_e18ad2cc-19bd-4f09-a024-8dec3d084d1f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DomesticPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_de061e24-50a0-4d03-8bf8-38dca02275a7" xlink:to="loc_us-gaap_DomesticPlanMember_e18ad2cc-19bd-4f09-a024-8dec3d084d1f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_US_a6ab0499-3e8a-4adb-9513-68657568ee4f" xlink:href="https://xbrl.sec.gov/country/2021/country-2021.xsd#country_US"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DomesticPlanMember_e18ad2cc-19bd-4f09-a024-8dec3d084d1f" xlink:to="loc_country_US_a6ab0499-3e8a-4adb-9513-68657568ee4f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignPlanMember_4d3f86d7-d2a3-4ae2-aa34-9eddca372d43" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ForeignPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_de061e24-50a0-4d03-8bf8-38dca02275a7" xlink:to="loc_us-gaap_ForeignPlanMember_4d3f86d7-d2a3-4ae2-aa34-9eddca372d43" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_5af94c6d-2877-40a2-a499-0307cac42e26" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetirementPlanTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_dc9498ea-3068-40c9-baf8-720fd5fc2f0a" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_5af94c6d-2877-40a2-a499-0307cac42e26" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_5af94c6d-2877-40a2-a499-0307cac42e26_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_5af94c6d-2877-40a2-a499-0307cac42e26" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_5af94c6d-2877-40a2-a499-0307cac42e26_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_7d1fabcf-a521-41c6-a02c-133ed9e013d1" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_5af94c6d-2877-40a2-a499-0307cac42e26" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_7d1fabcf-a521-41c6-a02c-133ed9e013d1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionPlansDefinedBenefitMember_d9a605eb-02b7-449c-973b-59b010903692" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PensionPlansDefinedBenefitMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_7d1fabcf-a521-41c6-a02c-133ed9e013d1" xlink:to="loc_us-gaap_PensionPlansDefinedBenefitMember_d9a605eb-02b7-449c-973b-59b010903692" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/EMPLOYEEBENEFITPLANSPensionPlanAssetsbyAssetCategoryDetails" xlink:type="simple" xlink:href="wab-20211231.xsd#EMPLOYEEBENEFITPLANSPensionPlanAssetsbyAssetCategoryDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/EMPLOYEEBENEFITPLANSPensionPlanAssetsbyAssetCategoryDetails" xlink:type="extended" id="iee7c976ec2c2446bb85e6178d3f1f8c8_EMPLOYEEBENEFITPLANSPensionPlanAssetsbyAssetCategoryDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_fb9b7378-2c6e-47cd-980b-b8759ce6d41f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_757f7eb0-1fd3-428c-ae8b-6815272aca46" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanFairValueOfPlanAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_fb9b7378-2c6e-47cd-980b-b8759ce6d41f" xlink:to="loc_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_757f7eb0-1fd3-428c-ae8b-6815272aca46" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_b2ccfd83-a057-4c22-b70b-8495ceb415c8" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_fb9b7378-2c6e-47cd-980b-b8759ce6d41f" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_b2ccfd83-a057-4c22-b70b-8495ceb415c8" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationAxis_96f14801-2b57-4dcb-9c89-09bec61352c4" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetirementPlanSponsorLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_b2ccfd83-a057-4c22-b70b-8495ceb415c8" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationAxis_96f14801-2b57-4dcb-9c89-09bec61352c4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_96f14801-2b57-4dcb-9c89-09bec61352c4_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_96f14801-2b57-4dcb-9c89-09bec61352c4" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_96f14801-2b57-4dcb-9c89-09bec61352c4_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_2abb7c7d-0699-45d0-bbc5-d2d7c4af93af" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_96f14801-2b57-4dcb-9c89-09bec61352c4" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_2abb7c7d-0699-45d0-bbc5-d2d7c4af93af" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DomesticPlanMember_f51b3edc-ed3a-48ce-b58e-3d298169bee2" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DomesticPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_2abb7c7d-0699-45d0-bbc5-d2d7c4af93af" xlink:to="loc_us-gaap_DomesticPlanMember_f51b3edc-ed3a-48ce-b58e-3d298169bee2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_US_b54e382a-012f-4f0e-b345-ea0d69008d0a" xlink:href="https://xbrl.sec.gov/country/2021/country-2021.xsd#country_US"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DomesticPlanMember_f51b3edc-ed3a-48ce-b58e-3d298169bee2" xlink:to="loc_country_US_b54e382a-012f-4f0e-b345-ea0d69008d0a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignPlanMember_b107bb53-b9a8-4b4e-a5f9-1ec557f51a42" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ForeignPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_2abb7c7d-0699-45d0-bbc5-d2d7c4af93af" xlink:to="loc_us-gaap_ForeignPlanMember_b107bb53-b9a8-4b4e-a5f9-1ec557f51a42" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_42025c31-c73e-44a3-91e8-675f9a9f276c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetirementPlanTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_b2ccfd83-a057-4c22-b70b-8495ceb415c8" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_42025c31-c73e-44a3-91e8-675f9a9f276c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_42025c31-c73e-44a3-91e8-675f9a9f276c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_42025c31-c73e-44a3-91e8-675f9a9f276c" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_42025c31-c73e-44a3-91e8-675f9a9f276c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_2e25509d-5f5c-4e7a-a5fd-749fd216b9ef" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_42025c31-c73e-44a3-91e8-675f9a9f276c" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_2e25509d-5f5c-4e7a-a5fd-749fd216b9ef" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionPlansDefinedBenefitMember_f23fae57-9247-406e-9e08-178afd274bc3" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PensionPlansDefinedBenefitMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_2e25509d-5f5c-4e7a-a5fd-749fd216b9ef" xlink:to="loc_us-gaap_PensionPlansDefinedBenefitMember_f23fae57-9247-406e-9e08-178afd274bc3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_7fcf05c5-e2df-4b7e-8aa9-6922db5e9368" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_b2ccfd83-a057-4c22-b70b-8495ceb415c8" xlink:to="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_7fcf05c5-e2df-4b7e-8aa9-6922db5e9368" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanAssetCategoriesDomain_7fcf05c5-e2df-4b7e-8aa9-6922db5e9368_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PlanAssetCategoriesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_7fcf05c5-e2df-4b7e-8aa9-6922db5e9368" xlink:to="loc_us-gaap_PlanAssetCategoriesDomain_7fcf05c5-e2df-4b7e-8aa9-6922db5e9368_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanAssetCategoriesDomain_639eaf9d-e570-4cff-8b63-6178cbb6219d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PlanAssetCategoriesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_7fcf05c5-e2df-4b7e-8aa9-6922db5e9368" xlink:to="loc_us-gaap_PlanAssetCategoriesDomain_639eaf9d-e570-4cff-8b63-6178cbb6219d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanEquitySecuritiesMember_67469362-75f3-4032-b24b-8d3676b04869" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanEquitySecuritiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_639eaf9d-e570-4cff-8b63-6178cbb6219d" xlink:to="loc_us-gaap_DefinedBenefitPlanEquitySecuritiesMember_67469362-75f3-4032-b24b-8d3676b04869" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanDebtSecurityMember_06394d51-fbfd-46d0-9552-8c336dacc590" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanDebtSecurityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_639eaf9d-e570-4cff-8b63-6178cbb6219d" xlink:to="loc_us-gaap_DefinedBenefitPlanDebtSecurityMember_06394d51-fbfd-46d0-9552-8c336dacc590" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_DefinedBenefitPlanInsuranceContractsMember_048437a3-44fd-4242-bdf7-09164d8610b0" xlink:href="wab-20211231.xsd#wab_DefinedBenefitPlanInsuranceContractsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_639eaf9d-e570-4cff-8b63-6178cbb6219d" xlink:to="loc_wab_DefinedBenefitPlanInsuranceContractsMember_048437a3-44fd-4242-bdf7-09164d8610b0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanCashAndCashEquivalentsMember_efdc1e5d-81d3-4bc0-9ea1-5527e73be680" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanCashAndCashEquivalentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_639eaf9d-e570-4cff-8b63-6178cbb6219d" xlink:to="loc_us-gaap_DefinedBenefitPlanCashAndCashEquivalentsMember_efdc1e5d-81d3-4bc0-9ea1-5527e73be680" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/EMPLOYEEBENEFITPLANSScheduleofPensionPlanAssetsMeasuredatFairValueDetails" xlink:type="simple" xlink:href="wab-20211231.xsd#EMPLOYEEBENEFITPLANSScheduleofPensionPlanAssetsMeasuredatFairValueDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/EMPLOYEEBENEFITPLANSScheduleofPensionPlanAssetsMeasuredatFairValueDetails" xlink:type="extended" id="i8ce24613469a46e5a5fcfe6fbbedaec4_EMPLOYEEBENEFITPLANSScheduleofPensionPlanAssetsMeasuredatFairValueDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_4245c5aa-7f12-4c84-9e03-b588f6859c08" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_10ecbe94-3629-4310-a3d7-da8d034440a8" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanFairValueOfPlanAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_4245c5aa-7f12-4c84-9e03-b588f6859c08" xlink:to="loc_us-gaap_DefinedBenefitPlanFairValueOfPlanAssets_10ecbe94-3629-4310-a3d7-da8d034440a8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_ed164f03-efc8-4005-b370-5604790d9dc5" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_4245c5aa-7f12-4c84-9e03-b588f6859c08" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_ed164f03-efc8-4005-b370-5604790d9dc5" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_e0cd074f-8938-4182-882a-ad2d7b709d57" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_ed164f03-efc8-4005-b370-5604790d9dc5" xlink:to="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_e0cd074f-8938-4182-882a-ad2d7b709d57" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanAssetCategoriesDomain_e0cd074f-8938-4182-882a-ad2d7b709d57_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PlanAssetCategoriesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_e0cd074f-8938-4182-882a-ad2d7b709d57" xlink:to="loc_us-gaap_PlanAssetCategoriesDomain_e0cd074f-8938-4182-882a-ad2d7b709d57_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanAssetCategoriesDomain_1f9c1c97-42d8-4bb2-8edd-535755f1a3ec" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PlanAssetCategoriesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis_e0cd074f-8938-4182-882a-ad2d7b709d57" xlink:to="loc_us-gaap_PlanAssetCategoriesDomain_1f9c1c97-42d8-4bb2-8edd-535755f1a3ec" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanEquitySecuritiesUsMember_ed063627-4098-4aa9-857b-a391a0125fb7" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanEquitySecuritiesUsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_1f9c1c97-42d8-4bb2-8edd-535755f1a3ec" xlink:to="loc_us-gaap_DefinedBenefitPlanEquitySecuritiesUsMember_ed063627-4098-4aa9-857b-a391a0125fb7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_DefinedBenefitPlanDebtSecurityAndOtherUSMember_c5dce687-2076-448c-9d8e-bff266ce2a17" xlink:href="wab-20211231.xsd#wab_DefinedBenefitPlanDebtSecurityAndOtherUSMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_1f9c1c97-42d8-4bb2-8edd-535755f1a3ec" xlink:to="loc_wab_DefinedBenefitPlanDebtSecurityAndOtherUSMember_c5dce687-2076-448c-9d8e-bff266ce2a17" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_DefinedBenefitPlanCashAndCashEquivalentsUSMember_71ce9e39-0cae-4683-80b4-2fec115e48f5" xlink:href="wab-20211231.xsd#wab_DefinedBenefitPlanCashAndCashEquivalentsUSMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_1f9c1c97-42d8-4bb2-8edd-535755f1a3ec" xlink:to="loc_wab_DefinedBenefitPlanCashAndCashEquivalentsUSMember_71ce9e39-0cae-4683-80b4-2fec115e48f5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanEquitySecuritiesNonUsMember_ebfb5126-5018-4e00-942f-da487d09c919" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanEquitySecuritiesNonUsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_1f9c1c97-42d8-4bb2-8edd-535755f1a3ec" xlink:to="loc_us-gaap_DefinedBenefitPlanEquitySecuritiesNonUsMember_ebfb5126-5018-4e00-942f-da487d09c919" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_DefinedBenefitPlanDebtSecuritiesAndOtherNonUSMember_e598b326-aac8-429d-9fbe-fbc18fc1fe17" xlink:href="wab-20211231.xsd#wab_DefinedBenefitPlanDebtSecuritiesAndOtherNonUSMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_1f9c1c97-42d8-4bb2-8edd-535755f1a3ec" xlink:to="loc_wab_DefinedBenefitPlanDebtSecuritiesAndOtherNonUSMember_e598b326-aac8-429d-9fbe-fbc18fc1fe17" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_DefinedBenefitPlanInsuranceContractsMember_2a16dbf9-cf6f-4d89-b41d-870831890fb0" xlink:href="wab-20211231.xsd#wab_DefinedBenefitPlanInsuranceContractsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_1f9c1c97-42d8-4bb2-8edd-535755f1a3ec" xlink:to="loc_wab_DefinedBenefitPlanInsuranceContractsMember_2a16dbf9-cf6f-4d89-b41d-870831890fb0" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_DefinedBenefitPlanCashAndCashEquivalentsNonUSMember_feea900b-c40a-4dac-80b9-51266bdbf711" xlink:href="wab-20211231.xsd#wab_DefinedBenefitPlanCashAndCashEquivalentsNonUSMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanAssetCategoriesDomain_1f9c1c97-42d8-4bb2-8edd-535755f1a3ec" xlink:to="loc_wab_DefinedBenefitPlanCashAndCashEquivalentsNonUSMember_feea900b-c40a-4dac-80b9-51266bdbf711" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_a52b8c8b-efc5-4e52-b27a-d25f08261e54" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_ed164f03-efc8-4005-b370-5604790d9dc5" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_a52b8c8b-efc5-4e52-b27a-d25f08261e54" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_a52b8c8b-efc5-4e52-b27a-d25f08261e54_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_a52b8c8b-efc5-4e52-b27a-d25f08261e54" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_a52b8c8b-efc5-4e52-b27a-d25f08261e54_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_bf48b3da-1a4d-4dd8-a9a1-ec25d523f75a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_a52b8c8b-efc5-4e52-b27a-d25f08261e54" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_bf48b3da-1a4d-4dd8-a9a1-ec25d523f75a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasuredAtNetAssetValuePerShareMember_f672e15d-81d9-4666-9ccd-75cc78897ffd" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueMeasuredAtNetAssetValuePerShareMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_bf48b3da-1a4d-4dd8-a9a1-ec25d523f75a" xlink:to="loc_us-gaap_FairValueMeasuredAtNetAssetValuePerShareMember_f672e15d-81d9-4666-9ccd-75cc78897ffd" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_43137039-7179-440c-9a95-1704b9093aba" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueInputsLevel1Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_bf48b3da-1a4d-4dd8-a9a1-ec25d523f75a" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_43137039-7179-440c-9a95-1704b9093aba" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_3072b290-1f1c-4855-8787-4d1173d1d7f2" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_bf48b3da-1a4d-4dd8-a9a1-ec25d523f75a" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_3072b290-1f1c-4855-8787-4d1173d1d7f2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_d5f93828-c109-4d93-a0c6-8d1a80ceecfa" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_bf48b3da-1a4d-4dd8-a9a1-ec25d523f75a" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_d5f93828-c109-4d93-a0c6-8d1a80ceecfa" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationAxis_3e1358b4-7f62-47c5-bccd-f2ba8960997d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetirementPlanSponsorLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_ed164f03-efc8-4005-b370-5604790d9dc5" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationAxis_3e1358b4-7f62-47c5-bccd-f2ba8960997d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_3e1358b4-7f62-47c5-bccd-f2ba8960997d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_3e1358b4-7f62-47c5-bccd-f2ba8960997d" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_3e1358b4-7f62-47c5-bccd-f2ba8960997d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_5cb45041-1bed-4193-8e3d-a3ecfa7c1399" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_3e1358b4-7f62-47c5-bccd-f2ba8960997d" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_5cb45041-1bed-4193-8e3d-a3ecfa7c1399" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DomesticPlanMember_3037b56f-52c5-497e-a75c-bb8bdedc907a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DomesticPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_5cb45041-1bed-4193-8e3d-a3ecfa7c1399" xlink:to="loc_us-gaap_DomesticPlanMember_3037b56f-52c5-497e-a75c-bb8bdedc907a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_US_6e5755ad-d513-4e29-bcac-46690b5df78a" xlink:href="https://xbrl.sec.gov/country/2021/country-2021.xsd#country_US"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DomesticPlanMember_3037b56f-52c5-497e-a75c-bb8bdedc907a" xlink:to="loc_country_US_6e5755ad-d513-4e29-bcac-46690b5df78a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignPlanMember_352e6cc0-9804-4064-a898-497c93bf3e7d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ForeignPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_5cb45041-1bed-4193-8e3d-a3ecfa7c1399" xlink:to="loc_us-gaap_ForeignPlanMember_352e6cc0-9804-4064-a898-497c93bf3e7d" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/EMPLOYEEBENEFITPLANSBenefitPaymentsExpectedtobePaidtoPlanParticipantsDetails" xlink:type="simple" xlink:href="wab-20211231.xsd#EMPLOYEEBENEFITPLANSBenefitPaymentsExpectedtobePaidtoPlanParticipantsDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/EMPLOYEEBENEFITPLANSBenefitPaymentsExpectedtobePaidtoPlanParticipantsDetails" xlink:type="extended" id="i0829d036a9b24a9db1df9ff4e1a56c52_EMPLOYEEBENEFITPLANSBenefitPaymentsExpectedtobePaidtoPlanParticipantsDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_264ea092-e0ab-41fe-bd3b-f01c65789b34" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths_6dc2ad7a-1fa7-4db4-9fa8-71359ea7419c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_264ea092-e0ab-41fe-bd3b-f01c65789b34" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths_6dc2ad7a-1fa7-4db4-9fa8-71359ea7419c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo_dd8043d1-0f3b-4435-9320-ae300f267ab5" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_264ea092-e0ab-41fe-bd3b-f01c65789b34" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo_dd8043d1-0f3b-4435-9320-ae300f267ab5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree_e3fc8d4a-8bb5-4633-9106-fb6a59e709aa" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_264ea092-e0ab-41fe-bd3b-f01c65789b34" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree_e3fc8d4a-8bb5-4633-9106-fb6a59e709aa" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour_9358a4ce-2deb-478f-8b2c-a3b0b41b1c1f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_264ea092-e0ab-41fe-bd3b-f01c65789b34" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour_9358a4ce-2deb-478f-8b2c-a3b0b41b1c1f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive_046ba557-ef2a-4d01-aace-ae2a6f94a442" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_264ea092-e0ab-41fe-bd3b-f01c65789b34" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive_046ba557-ef2a-4d01-aace-ae2a6f94a442" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter_66e98bb3-82e9-4fe0-87e9-874634364846" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_264ea092-e0ab-41fe-bd3b-f01c65789b34" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter_66e98bb3-82e9-4fe0-87e9-874634364846" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_034eca3d-df97-41d0-a26b-c56373c9b755" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_264ea092-e0ab-41fe-bd3b-f01c65789b34" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_034eca3d-df97-41d0-a26b-c56373c9b755" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationAxis_a702f7b1-9f5d-4089-9d69-702e09c40d24" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetirementPlanSponsorLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_034eca3d-df97-41d0-a26b-c56373c9b755" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationAxis_a702f7b1-9f5d-4089-9d69-702e09c40d24" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_a702f7b1-9f5d-4089-9d69-702e09c40d24_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_a702f7b1-9f5d-4089-9d69-702e09c40d24" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_a702f7b1-9f5d-4089-9d69-702e09c40d24_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanSponsorLocationDomain_4e5edf99-d7cf-4033-b8e3-d9349b298038" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetirementPlanSponsorLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationAxis_a702f7b1-9f5d-4089-9d69-702e09c40d24" xlink:to="loc_us-gaap_RetirementPlanSponsorLocationDomain_4e5edf99-d7cf-4033-b8e3-d9349b298038" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DomesticPlanMember_09ac543b-969a-4281-85c9-a8124c5e09cf" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DomesticPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_4e5edf99-d7cf-4033-b8e3-d9349b298038" xlink:to="loc_us-gaap_DomesticPlanMember_09ac543b-969a-4281-85c9-a8124c5e09cf" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_US_354b8737-dc40-4dd0-86de-0427c9e182f5" xlink:href="https://xbrl.sec.gov/country/2021/country-2021.xsd#country_US"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DomesticPlanMember_09ac543b-969a-4281-85c9-a8124c5e09cf" xlink:to="loc_country_US_354b8737-dc40-4dd0-86de-0427c9e182f5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignPlanMember_7bebbf99-c122-458e-90e6-d6558ad4050a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ForeignPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanSponsorLocationDomain_4e5edf99-d7cf-4033-b8e3-d9349b298038" xlink:to="loc_us-gaap_ForeignPlanMember_7bebbf99-c122-458e-90e6-d6558ad4050a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_d171205b-2329-4586-8a24-77345fe549f1" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetirementPlanTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_034eca3d-df97-41d0-a26b-c56373c9b755" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_d171205b-2329-4586-8a24-77345fe549f1" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_d171205b-2329-4586-8a24-77345fe549f1_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_d171205b-2329-4586-8a24-77345fe549f1" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_d171205b-2329-4586-8a24-77345fe549f1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_5d49edd6-9517-4901-935b-09b44cbfaad8" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_d171205b-2329-4586-8a24-77345fe549f1" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_5d49edd6-9517-4901-935b-09b44cbfaad8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionPlansDefinedBenefitMember_e21dc9a5-85fa-46e1-97e0-fcafdba8a0e4" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PensionPlansDefinedBenefitMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_5d49edd6-9517-4901-935b-09b44cbfaad8" xlink:to="loc_us-gaap_PensionPlansDefinedBenefitMember_e21dc9a5-85fa-46e1-97e0-fcafdba8a0e4" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/INCOMETAXESNarrativeDetails" xlink:type="simple" xlink:href="wab-20211231.xsd#INCOMETAXESNarrativeDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/INCOMETAXESNarrativeDetails" xlink:type="extended" id="i015ac46b22a24d9088106f21a572e083_INCOMETAXESNarrativeDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLossCarryforwardsLineItems_e22b3db1-a259-4cef-9f98-b22c903f0970" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OperatingLossCarryforwardsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLossCarryforwards_fdf2c92a-547e-4646-9dcc-8c5b753713d3" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OperatingLossCarryforwards"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingLossCarryforwardsLineItems_e22b3db1-a259-4cef-9f98-b22c903f0970" xlink:to="loc_us-gaap_OperatingLossCarryforwards_fdf2c92a-547e-4646-9dcc-8c5b753713d3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLossCarryforwardsTable_5faa6a92-d26e-4767-aee8-cc0f74dafa3a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OperatingLossCarryforwardsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_OperatingLossCarryforwardsLineItems_e22b3db1-a259-4cef-9f98-b22c903f0970" xlink:to="loc_us-gaap_OperatingLossCarryforwardsTable_5faa6a92-d26e-4767-aee8-cc0f74dafa3a" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TaxPeriodAxis_af7063af-e670-47b0-ad69-36955195ecbd" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TaxPeriodAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_OperatingLossCarryforwardsTable_5faa6a92-d26e-4767-aee8-cc0f74dafa3a" xlink:to="loc_us-gaap_TaxPeriodAxis_af7063af-e670-47b0-ad69-36955195ecbd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TaxPeriodDomain_af7063af-e670-47b0-ad69-36955195ecbd_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TaxPeriodDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_TaxPeriodAxis_af7063af-e670-47b0-ad69-36955195ecbd" xlink:to="loc_us-gaap_TaxPeriodDomain_af7063af-e670-47b0-ad69-36955195ecbd_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TaxPeriodDomain_f01fc186-905f-4cd6-8013-65868e272fdc" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TaxPeriodDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_TaxPeriodAxis_af7063af-e670-47b0-ad69-36955195ecbd" xlink:to="loc_us-gaap_TaxPeriodDomain_f01fc186-905f-4cd6-8013-65868e272fdc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_IndefiniteMember_5d9a3fbe-bbb6-4a01-888d-755fb02eee14" xlink:href="wab-20211231.xsd#wab_IndefiniteMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TaxPeriodDomain_f01fc186-905f-4cd6-8013-65868e272fdc" xlink:to="loc_wab_IndefiniteMember_5d9a3fbe-bbb6-4a01-888d-755fb02eee14" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_WithinTenYearsMember_45dda513-1a5c-46cd-b6ec-5d1a3e8d3872" xlink:href="wab-20211231.xsd#wab_WithinTenYearsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TaxPeriodDomain_f01fc186-905f-4cd6-8013-65868e272fdc" xlink:to="loc_wab_WithinTenYearsMember_45dda513-1a5c-46cd-b6ec-5d1a3e8d3872" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_BetweenDecember312032ToDecember312041Member_491378c2-0231-4b59-8e27-04371da5659b" xlink:href="wab-20211231.xsd#wab_BetweenDecember312032ToDecember312041Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TaxPeriodDomain_f01fc186-905f-4cd6-8013-65868e272fdc" xlink:to="loc_wab_BetweenDecember312032ToDecember312041Member_491378c2-0231-4b59-8e27-04371da5659b" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/STOCKBASEDCOMPENSATIONPLANSNarrativeDetails" xlink:type="simple" xlink:href="wab-20211231.xsd#STOCKBASEDCOMPENSATIONPLANSNarrativeDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/STOCKBASEDCOMPENSATIONPLANSNarrativeDetails" xlink:type="extended" id="i6dda49be60174e67b89e92162b491961_STOCKBASEDCOMPENSATIONPLANSNarrativeDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_246281ee-1e1d-4128-93cc-a4e7ae0ad8f6" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_a8c963e3-b908-4c0c-99e3-fda426b3a67f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_246281ee-1e1d-4128-93cc-a4e7ae0ad8f6" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_a8c963e3-b908-4c0c-99e3-fda426b3a67f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_c935942c-a87a-48fa-8dc8-5e8eb6d165d3" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_246281ee-1e1d-4128-93cc-a4e7ae0ad8f6" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_c935942c-a87a-48fa-8dc8-5e8eb6d165d3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_fc6da31c-b5dd-4a7f-b35f-4e6ae7f7a0f0" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_246281ee-1e1d-4128-93cc-a4e7ae0ad8f6" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_fc6da31c-b5dd-4a7f-b35f-4e6ae7f7a0f0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod_2e01281d-ccc9-45b6-88ab-cf242a1ef1d0" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_246281ee-1e1d-4128-93cc-a4e7ae0ad8f6" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod_2e01281d-ccc9-45b6-88ab-cf242a1ef1d0" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod_69777d27-804d-4290-bdde-cfadf87de411" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_246281ee-1e1d-4128-93cc-a4e7ae0ad8f6" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardSharesIssuedInPeriod_69777d27-804d-4290-bdde-cfadf87de411" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_21a6837c-6348-4c62-a429-ab3a6462e915" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_246281ee-1e1d-4128-93cc-a4e7ae0ad8f6" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_21a6837c-6348-4c62-a429-ab3a6462e915" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromExerciseOfStockOptions_b0883964-c2bc-484a-af71-ae60441886bc" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromExerciseOfStockOptions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_246281ee-1e1d-4128-93cc-a4e7ae0ad8f6" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromExerciseOfStockOptions_b0883964-c2bc-484a-af71-ae60441886bc" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_4de1b12f-fc15-4915-9747-879ac9ea6d5a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_246281ee-1e1d-4128-93cc-a4e7ae0ad8f6" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized_4de1b12f-fc15-4915-9747-879ac9ea6d5a" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_564bec49-2a42-4a20-9552-4010d5ba4d72" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_246281ee-1e1d-4128-93cc-a4e7ae0ad8f6" xlink:to="loc_us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1_564bec49-2a42-4a20-9552-4010d5ba4d72" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRateExpectedLife_4e5a0cd3-7203-44eb-a15a-9c2413021e73" xlink:href="wab-20211231.xsd#wab_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRateExpectedLife"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_246281ee-1e1d-4128-93cc-a4e7ae0ad8f6" xlink:to="loc_wab_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRateExpectedLife_4e5a0cd3-7203-44eb-a15a-9c2413021e73" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage_2454513f-e9a0-4896-8a6f-8e92a27a67b5" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_246281ee-1e1d-4128-93cc-a4e7ae0ad8f6" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage_2454513f-e9a0-4896-8a6f-8e92a27a67b5" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_a644012f-b59e-4ed2-9387-55ac53fb5074" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_246281ee-1e1d-4128-93cc-a4e7ae0ad8f6" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_a644012f-b59e-4ed2-9387-55ac53fb5074" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameAxis_b1c3f129-6ea9-4e6d-8ec9-94d042b1225a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PlanNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_a644012f-b59e-4ed2-9387-55ac53fb5074" xlink:to="loc_us-gaap_PlanNameAxis_b1c3f129-6ea9-4e6d-8ec9-94d042b1225a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_b1c3f129-6ea9-4e6d-8ec9-94d042b1225a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PlanNameAxis_b1c3f129-6ea9-4e6d-8ec9-94d042b1225a" xlink:to="loc_us-gaap_PlanNameDomain_b1c3f129-6ea9-4e6d-8ec9-94d042b1225a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_103ec4af-f8b5-4626-8117-d79cb30cc4b3" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PlanNameAxis_b1c3f129-6ea9-4e6d-8ec9-94d042b1225a" xlink:to="loc_us-gaap_PlanNameDomain_103ec4af-f8b5-4626-8117-d79cb30cc4b3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_PlanTwoThousandElevenMember_95963af2-3dc4-43cd-8818-b3212cd6c2d4" xlink:href="wab-20211231.xsd#wab_PlanTwoThousandElevenMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_103ec4af-f8b5-4626-8117-d79cb30cc4b3" xlink:to="loc_wab_PlanTwoThousandElevenMember_95963af2-3dc4-43cd-8818-b3212cd6c2d4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_DirectorsPlanMember_51d26704-35dd-4d81-ab87-d46d2f575207" xlink:href="wab-20211231.xsd#wab_DirectorsPlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_103ec4af-f8b5-4626-8117-d79cb30cc4b3" xlink:to="loc_wab_DirectorsPlanMember_51d26704-35dd-4d81-ab87-d46d2f575207" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_PlanTwoThousandMember_19e924ff-6e0f-4544-9984-ae4b4e197ef9" xlink:href="wab-20211231.xsd#wab_PlanTwoThousandMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_103ec4af-f8b5-4626-8117-d79cb30cc4b3" xlink:to="loc_wab_PlanTwoThousandMember_19e924ff-6e0f-4544-9984-ae4b4e197ef9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_c9ac7ab9-71f6-44a2-9732-8f680630cef1" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_a644012f-b59e-4ed2-9387-55ac53fb5074" xlink:to="loc_us-gaap_AwardTypeAxis_c9ac7ab9-71f6-44a2-9732-8f680630cef1" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_c9ac7ab9-71f6-44a2-9732-8f680630cef1_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_c9ac7ab9-71f6-44a2-9732-8f680630cef1" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_c9ac7ab9-71f6-44a2-9732-8f680630cef1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_dc302816-ed09-4b7f-b8e4-de9a866df8b1" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_c9ac7ab9-71f6-44a2-9732-8f680630cef1" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_dc302816-ed09-4b7f-b8e4-de9a866df8b1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockOptionMember_1dc12273-2ae8-463a-ae98-5f171089db99" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EmployeeStockOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_dc302816-ed09-4b7f-b8e4-de9a866df8b1" xlink:to="loc_us-gaap_EmployeeStockOptionMember_1dc12273-2ae8-463a-ae98-5f171089db99" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockMember_10345819-9cc8-432a-81f2-865f9bb45971" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RestrictedStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_dc302816-ed09-4b7f-b8e4-de9a866df8b1" xlink:to="loc_us-gaap_RestrictedStockMember_10345819-9cc8-432a-81f2-865f9bb45971" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_NonVestedRestrictedStockMember_816924d2-d620-44f9-89e3-f0e721498752" xlink:href="wab-20211231.xsd#wab_NonVestedRestrictedStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_dc302816-ed09-4b7f-b8e4-de9a866df8b1" xlink:to="loc_wab_NonVestedRestrictedStockMember_816924d2-d620-44f9-89e3-f0e721498752" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_8f525b42-d06b-4f2c-8cf8-3a7d2c8827c3" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RestrictedStockUnitsRSUMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_dc302816-ed09-4b7f-b8e4-de9a866df8b1" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_8f525b42-d06b-4f2c-8cf8-3a7d2c8827c3" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PerformanceSharesMember_6cda59d8-f5c9-49fe-a454-6a97f49620fc" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PerformanceSharesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_dc302816-ed09-4b7f-b8e4-de9a866df8b1" xlink:to="loc_us-gaap_PerformanceSharesMember_6cda59d8-f5c9-49fe-a454-6a97f49620fc" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_5a752f3e-9573-4c9a-9972-661311da4b9d" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_a644012f-b59e-4ed2-9387-55ac53fb5074" xlink:to="loc_srt_RangeAxis_5a752f3e-9573-4c9a-9972-661311da4b9d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_5a752f3e-9573-4c9a-9972-661311da4b9d_default" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_5a752f3e-9573-4c9a-9972-661311da4b9d" xlink:to="loc_srt_RangeMember_5a752f3e-9573-4c9a-9972-661311da4b9d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_31e8cc8c-3a05-4d9b-a272-eaa13a6acddd" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_5a752f3e-9573-4c9a-9972-661311da4b9d" xlink:to="loc_srt_RangeMember_31e8cc8c-3a05-4d9b-a272-eaa13a6acddd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_3d37d4a0-71b7-42a1-85c4-ce2a3f584111" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_31e8cc8c-3a05-4d9b-a272-eaa13a6acddd" xlink:to="loc_srt_MinimumMember_3d37d4a0-71b7-42a1-85c4-ce2a3f584111" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_a9c7e2c3-03fe-4374-b9bc-7a056faa16e5" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_31e8cc8c-3a05-4d9b-a272-eaa13a6acddd" xlink:to="loc_srt_MaximumMember_a9c7e2c3-03fe-4374-b9bc-7a056faa16e5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementScenarioAxis_2db999ed-b9cd-488d-8229-d314682d4ce3" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_StatementScenarioAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_a644012f-b59e-4ed2-9387-55ac53fb5074" xlink:to="loc_srt_StatementScenarioAxis_2db999ed-b9cd-488d-8229-d314682d4ce3" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScenarioUnspecifiedDomain_2db999ed-b9cd-488d-8229-d314682d4ce3_default" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_ScenarioUnspecifiedDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementScenarioAxis_2db999ed-b9cd-488d-8229-d314682d4ce3" xlink:to="loc_srt_ScenarioUnspecifiedDomain_2db999ed-b9cd-488d-8229-d314682d4ce3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScenarioUnspecifiedDomain_6429e4fc-cf57-4a5f-a66d-06c4af4563a4" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_ScenarioUnspecifiedDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementScenarioAxis_2db999ed-b9cd-488d-8229-d314682d4ce3" xlink:to="loc_srt_ScenarioUnspecifiedDomain_6429e4fc-cf57-4a5f-a66d-06c4af4563a4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScenarioForecastMember_254e5d8c-0c81-4215-9b7d-23ff90c446f4" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_ScenarioForecastMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ScenarioUnspecifiedDomain_6429e4fc-cf57-4a5f-a66d-06c4af4563a4" xlink:to="loc_srt_ScenarioForecastMember_254e5d8c-0c81-4215-9b7d-23ff90c446f4" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/STOCKBASEDCOMPENSATIONPLANSStockOptionsOutstandingDetails" xlink:type="simple" xlink:href="wab-20211231.xsd#STOCKBASEDCOMPENSATIONPLANSStockOptionsOutstandingDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/STOCKBASEDCOMPENSATIONPLANSStockOptionsOutstandingDetails" xlink:type="extended" id="ifb5ee1467772445b8d1b73aa57a1b79b_STOCKBASEDCOMPENSATIONPLANSStockOptionsOutstandingDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems_299c4396-2d6d-41ce-8bc4-00346dd7fcf4" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLowerRangeLimit_d742e493-a570-4827-a1df-f8277023cade" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLowerRangeLimit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems_299c4396-2d6d-41ce-8bc4-00346dd7fcf4" xlink:to="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLowerRangeLimit_d742e493-a570-4827-a1df-f8277023cade" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit_cf9cc316-f4a8-4f12-9730-963845acb151" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems_299c4396-2d6d-41ce-8bc4-00346dd7fcf4" xlink:to="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeUpperRangeLimit_cf9cc316-f4a8-4f12-9730-963845acb151" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfOutstandingOptions_a47bdec8-4d74-4fdd-b07b-d91924464098" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfOutstandingOptions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems_299c4396-2d6d-41ce-8bc4-00346dd7fcf4" xlink:to="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfOutstandingOptions_a47bdec8-4d74-4fdd-b07b-d91924464098" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeOutstandingOptionsWeightedAverageExercisePriceBeginningBalance1_ee8dc2ce-1f6e-4b79-b5f2-aa2d2cb407a8" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeOutstandingOptionsWeightedAverageExercisePriceBeginningBalance1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems_299c4396-2d6d-41ce-8bc4-00346dd7fcf4" xlink:to="loc_us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeOutstandingOptionsWeightedAverageExercisePriceBeginningBalance1_ee8dc2ce-1f6e-4b79-b5f2-aa2d2cb407a8" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeOutstandingOptionsWeightedAverageRemainingContractualTerm2_6a77a9a2-2b3b-4e44-9513-cc32f99991d3" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeOutstandingOptionsWeightedAverageRemainingContractualTerm2"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems_299c4396-2d6d-41ce-8bc4-00346dd7fcf4" xlink:to="loc_us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeOutstandingOptionsWeightedAverageRemainingContractualTerm2_6a77a9a2-2b3b-4e44-9513-cc32f99991d3" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfExercisableOptions_81b8023c-fdbf-47e7-b176-4ede2664aa4b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfExercisableOptions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems_299c4396-2d6d-41ce-8bc4-00346dd7fcf4" xlink:to="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeNumberOfExercisableOptions_81b8023c-fdbf-47e7-b176-4ede2664aa4b" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeExercisableOptionsWeightedAverageExercisePrice1_5c6e84d2-de7c-4120-af91-2b8d4d4e8083" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeExercisableOptionsWeightedAverageExercisePrice1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems_299c4396-2d6d-41ce-8bc4-00346dd7fcf4" xlink:to="loc_us-gaap_SharebasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeExercisableOptionsWeightedAverageExercisePrice1_5c6e84d2-de7c-4120-af91-2b8d4d4e8083" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeTable_c89df15b-ac70-4bfc-ad15-5915411bae51" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeLineItems_299c4396-2d6d-41ce-8bc4-00346dd7fcf4" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeTable_c89df15b-ac70-4bfc-ad15-5915411bae51" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis_7898638f-4fbc-4ec7-ba6f-210cd3c42a42" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeTable_c89df15b-ac70-4bfc-ad15-5915411bae51" xlink:to="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis_7898638f-4fbc-4ec7-ba6f-210cd3c42a42" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain_7898638f-4fbc-4ec7-ba6f-210cd3c42a42_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis_7898638f-4fbc-4ec7-ba6f-210cd3c42a42" xlink:to="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain_7898638f-4fbc-4ec7-ba6f-210cd3c42a42_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain_3b0497af-fc7e-4c0b-b973-5bfc0f716b56" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansByExercisePriceRangeAxis_7898638f-4fbc-4ec7-ba6f-210cd3c42a42" xlink:to="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain_3b0497af-fc7e-4c0b-b973-5bfc0f716b56" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_ExercisePriceRangeTwoMember_046a8eb1-fbf6-4fd2-9071-d77f39fdbadf" xlink:href="wab-20211231.xsd#wab_ExercisePriceRangeTwoMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain_3b0497af-fc7e-4c0b-b973-5bfc0f716b56" xlink:to="loc_wab_ExercisePriceRangeTwoMember_046a8eb1-fbf6-4fd2-9071-d77f39fdbadf" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_ExercisePriceRangeThreeMember_7a38d0b9-b56f-47ce-9644-13a7c22bb7d4" xlink:href="wab-20211231.xsd#wab_ExercisePriceRangeThreeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain_3b0497af-fc7e-4c0b-b973-5bfc0f716b56" xlink:to="loc_wab_ExercisePriceRangeThreeMember_7a38d0b9-b56f-47ce-9644-13a7c22bb7d4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_ExercisePriceRangeFourMember_e930b9e7-5343-4bf7-944b-c8e9e8e439b2" xlink:href="wab-20211231.xsd#wab_ExercisePriceRangeFourMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain_3b0497af-fc7e-4c0b-b973-5bfc0f716b56" xlink:to="loc_wab_ExercisePriceRangeFourMember_e930b9e7-5343-4bf7-944b-c8e9e8e439b2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_ExercisePriceRangeFiveMember_cd30e187-3efe-4a69-8c8f-ca43b8e9f528" xlink:href="wab-20211231.xsd#wab_ExercisePriceRangeFiveMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationSharesAuthorizedUnderStockOptionPlansExercisePriceRangeDomain_3b0497af-fc7e-4c0b-b973-5bfc0f716b56" xlink:to="loc_wab_ExercisePriceRangeFiveMember_cd30e187-3efe-4a69-8c8f-ca43b8e9f528" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/STOCKBASEDCOMPENSATIONPLANSRestrictedStockActivityandIncentiveStockAwardsActivityDetails" xlink:type="simple" xlink:href="wab-20211231.xsd#STOCKBASEDCOMPENSATIONPLANSRestrictedStockActivityandIncentiveStockAwardsActivityDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/STOCKBASEDCOMPENSATIONPLANSRestrictedStockActivityandIncentiveStockAwardsActivityDetails" xlink:type="extended" id="i1ee51eab50c84850a4befa4d29406077_STOCKBASEDCOMPENSATIONPLANSRestrictedStockActivityandIncentiveStockAwardsActivityDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_0060094f-c204-4383-95e5-1c2d27383eec" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_f4da2ded-5945-43d8-8d9b-c9f274d383ca" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_0060094f-c204-4383-95e5-1c2d27383eec" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_f4da2ded-5945-43d8-8d9b-c9f274d383ca" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_aed2c001-f80d-4966-a049-c731ab8c9c6b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_f4da2ded-5945-43d8-8d9b-c9f274d383ca" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_aed2c001-f80d-4966-a049-c731ab8c9c6b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_7f3a9331-6d8c-47f1-bcb5-ab2b77ee25e8" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_f4da2ded-5945-43d8-8d9b-c9f274d383ca" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_7f3a9331-6d8c-47f1-bcb5-ab2b77ee25e8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_880ba576-a6eb-406c-9f2d-d21bd52355cc" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_f4da2ded-5945-43d8-8d9b-c9f274d383ca" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_880ba576-a6eb-406c-9f2d-d21bd52355cc" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumberExpectedToVest_e0eabfc2-0da2-443f-b586-157fbd251839" xlink:href="wab-20211231.xsd#wab_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumberExpectedToVest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_f4da2ded-5945-43d8-8d9b-c9f274d383ca" xlink:to="loc_wab_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumberExpectedToVest_e0eabfc2-0da2-443f-b586-157fbd251839" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_652cb3a6-ac52-4860-b8a1-eb6d7eccd6f8" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_f4da2ded-5945-43d8-8d9b-c9f274d383ca" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_652cb3a6-ac52-4860-b8a1-eb6d7eccd6f8" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_b06dffa6-56da-401a-9625-478c678c6118" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_cd933898-5a54-46a6-a9f9-835e62633983" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_0060094f-c204-4383-95e5-1c2d27383eec" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_cd933898-5a54-46a6-a9f9-835e62633983" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_6bf29568-60cb-4246-8abb-05a9280e6a83" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_cd933898-5a54-46a6-a9f9-835e62633983" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_6bf29568-60cb-4246-8abb-05a9280e6a83" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_f3a14503-31a1-4ccf-8562-f40e0db5089f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_cd933898-5a54-46a6-a9f9-835e62633983" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_f3a14503-31a1-4ccf-8562-f40e0db5089f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_f815fd26-308f-49ec-960c-ca74a8fddb08" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_cd933898-5a54-46a6-a9f9-835e62633983" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_f815fd26-308f-49ec-960c-ca74a8fddb08" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNetPerformanceAdjustmentWeightedAverageNetPerformanceAdjustmentFairValue_eb190e35-dce5-48f0-8bee-2b0cef058802" xlink:href="wab-20211231.xsd#wab_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNetPerformanceAdjustmentWeightedAverageNetPerformanceAdjustmentFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_cd933898-5a54-46a6-a9f9-835e62633983" xlink:to="loc_wab_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNetPerformanceAdjustmentWeightedAverageNetPerformanceAdjustmentFairValue_eb190e35-dce5-48f0-8bee-2b0cef058802" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_05f00a74-9756-4967-b0cd-9661258b332b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_cd933898-5a54-46a6-a9f9-835e62633983" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_05f00a74-9756-4967-b0cd-9661258b332b" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_d3400d0d-c2ea-4a97-bd7e-6e9da9bc769a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_145b3a90-959c-4c43-b1aa-2545c71a09fa" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_0060094f-c204-4383-95e5-1c2d27383eec" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_145b3a90-959c-4c43-b1aa-2545c71a09fa" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_50a9ccf9-5658-4dfc-8457-2af72de91614" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_145b3a90-959c-4c43-b1aa-2545c71a09fa" xlink:to="loc_us-gaap_AwardTypeAxis_50a9ccf9-5658-4dfc-8457-2af72de91614" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_50a9ccf9-5658-4dfc-8457-2af72de91614_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_50a9ccf9-5658-4dfc-8457-2af72de91614" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_50a9ccf9-5658-4dfc-8457-2af72de91614_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_53bc6279-962b-4e07-987f-e4be1189fca2" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_50a9ccf9-5658-4dfc-8457-2af72de91614" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_53bc6279-962b-4e07-987f-e4be1189fca2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_RestrictedStockAndUnitsMember_a752666c-3144-4e9d-a12c-04f7d39e3531" xlink:href="wab-20211231.xsd#wab_RestrictedStockAndUnitsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_53bc6279-962b-4e07-987f-e4be1189fca2" xlink:to="loc_wab_RestrictedStockAndUnitsMember_a752666c-3144-4e9d-a12c-04f7d39e3531" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PerformanceSharesMember_7d212e40-0089-4689-a08e-81745b0dc55a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PerformanceSharesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_53bc6279-962b-4e07-987f-e4be1189fca2" xlink:to="loc_us-gaap_PerformanceSharesMember_7d212e40-0089-4689-a08e-81745b0dc55a" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/ACCUMULATEDOTHERCOMPREHENSIVELOSSDetails" xlink:type="simple" xlink:href="wab-20211231.xsd#ACCUMULATEDOTHERCOMPREHENSIVELOSSDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/ACCUMULATEDOTHERCOMPREHENSIVELOSSDetails" xlink:type="extended" id="ieca835a3ef5d422dbc53a31eba83a8c1_ACCUMULATEDOTHERCOMPREHENSIVELOSSDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_524d61c3-f17d-45a7-9722-15bfa2e2c021" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_529ea8cd-9809-42e6-ac9e-78228e22bc5a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AOCIAttributableToParentNetOfTaxRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_524d61c3-f17d-45a7-9722-15bfa2e2c021" xlink:to="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_529ea8cd-9809-42e6-ac9e-78228e22bc5a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_823a6ead-5920-42c8-8f73-520aa4d1fc78" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_529ea8cd-9809-42e6-ac9e-78228e22bc5a" xlink:to="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_823a6ead-5920-42c8-8f73-520aa4d1fc78" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax_1370d7aa-6864-4494-bd0d-1b497ae81c6e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_529ea8cd-9809-42e6-ac9e-78228e22bc5a" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax_1370d7aa-6864-4494-bd0d-1b497ae81c6e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax_eb3a8e1a-9b16-4216-adce-059afd64eeb1" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_529ea8cd-9809-42e6-ac9e-78228e22bc5a" xlink:to="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax_eb3a8e1a-9b16-4216-adce-059afd64eeb1" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_4b3852f8-fd60-46e3-af06-261805ee96fe" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AOCIAttributableToParentNetOfTaxRollForward_529ea8cd-9809-42e6-ac9e-78228e22bc5a" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_4b3852f8-fd60-46e3-af06-261805ee96fe" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_19502385-27b5-4094-ad58-a9bb48a0862f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_a2207fbe-82d7-4a48-a755-851ef1d4c264" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_524d61c3-f17d-45a7-9722-15bfa2e2c021" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_a2207fbe-82d7-4a48-a755-851ef1d4c264" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_cbdf74c5-22da-4527-ac74-60a19fa6dcc3" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_a2207fbe-82d7-4a48-a755-851ef1d4c264" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_cbdf74c5-22da-4527-ac74-60a19fa6dcc3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_cbdf74c5-22da-4527-ac74-60a19fa6dcc3_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_cbdf74c5-22da-4527-ac74-60a19fa6dcc3" xlink:to="loc_us-gaap_EquityComponentDomain_cbdf74c5-22da-4527-ac74-60a19fa6dcc3_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_75cbd7e6-de87-4ada-a5ce-ea8a3481d942" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_cbdf74c5-22da-4527-ac74-60a19fa6dcc3" xlink:to="loc_us-gaap_EquityComponentDomain_75cbd7e6-de87-4ada-a5ce-ea8a3481d942" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedTranslationAdjustmentMember_9c0d7481-f088-48ed-989e-8f20d1e6635a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccumulatedTranslationAdjustmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_75cbd7e6-de87-4ada-a5ce-ea8a3481d942" xlink:to="loc_us-gaap_AccumulatedTranslationAdjustmentMember_9c0d7481-f088-48ed-989e-8f20d1e6635a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember_fc5f74fb-7f2e-4c24-8034-a368574cbd13" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_75cbd7e6-de87-4ada-a5ce-ea8a3481d942" xlink:to="loc_us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember_fc5f74fb-7f2e-4c24-8034-a368574cbd13" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember_5298f4cf-d582-44a5-82f5-8d8d82f992fc" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_75cbd7e6-de87-4ada-a5ce-ea8a3481d942" xlink:to="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember_5298f4cf-d582-44a5-82f5-8d8d82f992fc" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_bc44d902-c893-4da4-9019-2b92cc519a1b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_75cbd7e6-de87-4ada-a5ce-ea8a3481d942" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_bc44d902-c893-4da4-9019-2b92cc519a1b" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/LEASESNarrativeDetails" xlink:type="simple" xlink:href="wab-20211231.xsd#LEASESNarrativeDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/LEASESNarrativeDetails" xlink:type="extended" id="idfd36dd0bc384c9690cac1bc3c92bd0d_LEASESNarrativeDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeasedAssetsLineItems_5d2935f8-c2e4-4f1e-9031-9c17573f71a7" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OperatingLeasedAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingLeaseCost_ae2c6047-52bf-41fd-8e41-142849060da5" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OperatingLeaseCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingLeasedAssetsLineItems_5d2935f8-c2e4-4f1e-9031-9c17573f71a7" xlink:to="loc_us-gaap_OperatingLeaseCost_ae2c6047-52bf-41fd-8e41-142849060da5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CapitalLeaseObligationsIncurred_aa76aeae-f3ab-4029-872e-d7d414041f8c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CapitalLeaseObligationsIncurred"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingLeasedAssetsLineItems_5d2935f8-c2e4-4f1e-9031-9c17573f71a7" xlink:to="loc_us-gaap_CapitalLeaseObligationsIncurred_aa76aeae-f3ab-4029-872e-d7d414041f8c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_LesseeWeightedAverageDiscountRatePercent_bf6efeea-1b86-4221-bb71-e585d053cc28" xlink:href="wab-20211231.xsd#wab_LesseeWeightedAverageDiscountRatePercent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingLeasedAssetsLineItems_5d2935f8-c2e4-4f1e-9031-9c17573f71a7" xlink:to="loc_wab_LesseeWeightedAverageDiscountRatePercent_bf6efeea-1b86-4221-bb71-e585d053cc28" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfOperatingLeasedAssetsTable_8bb16000-5c0e-4ba0-b655-21660fff76a2" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfOperatingLeasedAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_OperatingLeasedAssetsLineItems_5d2935f8-c2e4-4f1e-9031-9c17573f71a7" xlink:to="loc_us-gaap_ScheduleOfOperatingLeasedAssetsTable_8bb16000-5c0e-4ba0-b655-21660fff76a2" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_6f7d6e43-a08c-41f7-93d0-dff96eb56210" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfOperatingLeasedAssetsTable_8bb16000-5c0e-4ba0-b655-21660fff76a2" xlink:to="loc_srt_RangeAxis_6f7d6e43-a08c-41f7-93d0-dff96eb56210" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_6f7d6e43-a08c-41f7-93d0-dff96eb56210_default" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_6f7d6e43-a08c-41f7-93d0-dff96eb56210" xlink:to="loc_srt_RangeMember_6f7d6e43-a08c-41f7-93d0-dff96eb56210_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_2616148e-f15e-402a-9c0d-9e339f170086" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_6f7d6e43-a08c-41f7-93d0-dff96eb56210" xlink:to="loc_srt_RangeMember_2616148e-f15e-402a-9c0d-9e339f170086" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_152eef27-8282-42cb-ba76-ba9f2d8997ab" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_2616148e-f15e-402a-9c0d-9e339f170086" xlink:to="loc_srt_MinimumMember_152eef27-8282-42cb-ba76-ba9f2d8997ab" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_d2c01c12-d060-456e-89d0-5b4bd24463e8" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_2616148e-f15e-402a-9c0d-9e339f170086" xlink:to="loc_srt_MaximumMember_d2c01c12-d060-456e-89d0-5b4bd24463e8" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/FAIRVALUEMEASUREMENTANDDERIVATIVEINSTRUMENTSNarrativeDetails" xlink:type="simple" xlink:href="wab-20211231.xsd#FAIRVALUEMEASUREMENTANDDERIVATIVEINSTRUMENTSNarrativeDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/FAIRVALUEMEASUREMENTANDDERIVATIVEINSTRUMENTSNarrativeDetails" xlink:type="extended" id="i0bc411e49a02436697da11b5fc3ba29c_FAIRVALUEMEASUREMENTANDDERIVATIVEINSTRUMENTSNarrativeDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_7239f391-d5bd-4470-8ebe-6260442efd6c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationContingentConsiderationLiability_2da2ae71-b1a6-45e1-b36f-84fe7766dffa" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessCombinationContingentConsiderationLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_7239f391-d5bd-4470-8ebe-6260442efd6c" xlink:to="loc_us-gaap_BusinessCombinationContingentConsiderationLiability_2da2ae71-b1a6-45e1-b36f-84fe7766dffa" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProductWarrantyAccrualNoncurrent_55e15d65-3bba-40e7-b038-849cbcafcbcd" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProductWarrantyAccrualNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_7239f391-d5bd-4470-8ebe-6260442efd6c" xlink:to="loc_us-gaap_ProductWarrantyAccrualNoncurrent_55e15d65-3bba-40e7-b038-849cbcafcbcd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnrealizedGainLossOnDerivatives_be65cf03-c864-4e9b-afaa-206953d2d5a2" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_UnrealizedGainLossOnDerivatives"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_7239f391-d5bd-4470-8ebe-6260442efd6c" xlink:to="loc_us-gaap_UnrealizedGainLossOnDerivatives_be65cf03-c864-4e9b-afaa-206953d2d5a2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeTermOfContract_2ef6c4d2-f23a-4dd2-a3f4-7a927b4be41e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeTermOfContract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_7239f391-d5bd-4470-8ebe-6260442efd6c" xlink:to="loc_us-gaap_DerivativeTermOfContract_2ef6c4d2-f23a-4dd2-a3f4-7a927b4be41e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_61e0e14e-fb61-4a10-bea8-8adcd65adfc8" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_7239f391-d5bd-4470-8ebe-6260442efd6c" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_61e0e14e-fb61-4a10-bea8-8adcd65adfc8" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalanceSheetLocationAxis_7c10b050-4014-431a-9788-3f78947cc6cc" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BalanceSheetLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_61e0e14e-fb61-4a10-bea8-8adcd65adfc8" xlink:to="loc_us-gaap_BalanceSheetLocationAxis_7c10b050-4014-431a-9788-3f78947cc6cc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_7c10b050-4014-431a-9788-3f78947cc6cc_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BalanceSheetLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_7c10b050-4014-431a-9788-3f78947cc6cc" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_7c10b050-4014-431a-9788-3f78947cc6cc_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_580e59c2-d5c3-4fbe-851f-abcbe236f102" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BalanceSheetLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_7c10b050-4014-431a-9788-3f78947cc6cc" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_580e59c2-d5c3-4fbe-851f-abcbe236f102" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_OtherAccruedLiabilitiesMember_305941ce-62c1-4bd7-8325-1497d6b8836a" xlink:href="wab-20211231.xsd#wab_OtherAccruedLiabilitiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_580e59c2-d5c3-4fbe-851f-abcbe236f102" xlink:to="loc_wab_OtherAccruedLiabilitiesMember_305941ce-62c1-4bd7-8325-1497d6b8836a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_9d7f249d-06e8-4f2e-97a0-08433b6c571a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_61e0e14e-fb61-4a10-bea8-8adcd65adfc8" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_9d7f249d-06e8-4f2e-97a0-08433b6c571a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_9d7f249d-06e8-4f2e-97a0-08433b6c571a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_9d7f249d-06e8-4f2e-97a0-08433b6c571a" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_9d7f249d-06e8-4f2e-97a0-08433b6c571a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_5d6267b8-7b48-4d72-96f3-fbb349d03503" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_9d7f249d-06e8-4f2e-97a0-08433b6c571a" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_5d6267b8-7b48-4d72-96f3-fbb349d03503" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_GeneralElectricCompanyMember_18f9e7f0-79cd-4f57-aca3-dc0dbcfb5752" xlink:href="wab-20211231.xsd#wab_GeneralElectricCompanyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_5d6267b8-7b48-4d72-96f3-fbb349d03503" xlink:to="loc_wab_GeneralElectricCompanyMember_18f9e7f0-79cd-4f57-aca3-dc0dbcfb5752" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_15012b2a-003e-4612-9951-9b6f25f2b31e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_61e0e14e-fb61-4a10-bea8-8adcd65adfc8" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_15012b2a-003e-4612-9951-9b6f25f2b31e" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_15012b2a-003e-4612-9951-9b6f25f2b31e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_15012b2a-003e-4612-9951-9b6f25f2b31e" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_15012b2a-003e-4612-9951-9b6f25f2b31e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_aba980ff-3bb5-4f75-aee3-2d80416956ba" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_15012b2a-003e-4612-9951-9b6f25f2b31e" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_aba980ff-3bb5-4f75-aee3-2d80416956ba" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_cd55b131-751e-4d5d-926a-1347dc960777" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_aba980ff-3bb5-4f75-aee3-2d80416956ba" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_cd55b131-751e-4d5d-926a-1347dc960777" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_86fd6edd-58f3-4dbb-9d4f-bb44a357dcec" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_61e0e14e-fb61-4a10-bea8-8adcd65adfc8" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_86fd6edd-58f3-4dbb-9d4f-bb44a357dcec" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_86fd6edd-58f3-4dbb-9d4f-bb44a357dcec_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_86fd6edd-58f3-4dbb-9d4f-bb44a357dcec" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_86fd6edd-58f3-4dbb-9d4f-bb44a357dcec_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_555f390f-cf13-4f8d-a82c-42f822726dac" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_86fd6edd-58f3-4dbb-9d4f-bb44a357dcec" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_555f390f-cf13-4f8d-a82c-42f822726dac" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignExchangeForwardMember_a11d6a5e-f8cf-414e-a65e-92abebe11cb8" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ForeignExchangeForwardMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_555f390f-cf13-4f8d-a82c-42f822726dac" xlink:to="loc_us-gaap_ForeignExchangeForwardMember_a11d6a5e-f8cf-414e-a65e-92abebe11cb8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationAxis_741c62fe-1d2f-4d2f-b57c-e5440563c6c6" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_HedgingDesignationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_61e0e14e-fb61-4a10-bea8-8adcd65adfc8" xlink:to="loc_us-gaap_HedgingDesignationAxis_741c62fe-1d2f-4d2f-b57c-e5440563c6c6" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_741c62fe-1d2f-4d2f-b57c-e5440563c6c6_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_HedgingDesignationAxis_741c62fe-1d2f-4d2f-b57c-e5440563c6c6" xlink:to="loc_us-gaap_HedgingDesignationDomain_741c62fe-1d2f-4d2f-b57c-e5440563c6c6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_3925964d-aa9a-4b07-9943-645100695e02" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_HedgingDesignationAxis_741c62fe-1d2f-4d2f-b57c-e5440563c6c6" xlink:to="loc_us-gaap_HedgingDesignationDomain_3925964d-aa9a-4b07-9943-645100695e02" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NondesignatedMember_8f325be6-8883-436f-8783-e1bbe08c81f0" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NondesignatedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_3925964d-aa9a-4b07-9943-645100695e02" xlink:to="loc_us-gaap_NondesignatedMember_8f325be6-8883-436f-8783-e1bbe08c81f0" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/FAIRVALUEMEASUREMENTANDDERIVATIVEINSTRUMENTSSummaryofAssetsLiabilitiesandGrossNotionalAmountsDetails" xlink:type="simple" xlink:href="wab-20211231.xsd#FAIRVALUEMEASUREMENTANDDERIVATIVEINSTRUMENTSSummaryofAssetsLiabilitiesandGrossNotionalAmountsDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/FAIRVALUEMEASUREMENTANDDERIVATIVEINSTRUMENTSSummaryofAssetsLiabilitiesandGrossNotionalAmountsDetails" xlink:type="extended" id="iab1794f050994ca0a79517079095d5c7_FAIRVALUEMEASUREMENTANDDERIVATIVEINSTRUMENTSSummaryofAssetsLiabilitiesandGrossNotionalAmountsDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_27ad224c-4383-4095-91fe-4a8b2cf05f9c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeFairValueOfDerivativeAsset_0c30fec5-f59e-49a0-b32a-d3c520ff74c2" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeFairValueOfDerivativeAsset"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_27ad224c-4383-4095-91fe-4a8b2cf05f9c" xlink:to="loc_us-gaap_DerivativeFairValueOfDerivativeAsset_0c30fec5-f59e-49a0-b32a-d3c520ff74c2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeFairValueOfDerivativeLiability_ec34edd1-3dfa-4e07-b5cd-8f3fa276da7c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeFairValueOfDerivativeLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_27ad224c-4383-4095-91fe-4a8b2cf05f9c" xlink:to="loc_us-gaap_DerivativeFairValueOfDerivativeLiability_ec34edd1-3dfa-4e07-b5cd-8f3fa276da7c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeFairValueOfDerivativeNet_cf670022-21dd-435f-813e-68c3cf127460" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeFairValueOfDerivativeNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_27ad224c-4383-4095-91fe-4a8b2cf05f9c" xlink:to="loc_us-gaap_DerivativeFairValueOfDerivativeNet_cf670022-21dd-435f-813e-68c3cf127460" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeNotionalAmount_bf9cb924-ce86-47f4-a41b-047636549f1f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeNotionalAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_27ad224c-4383-4095-91fe-4a8b2cf05f9c" xlink:to="loc_us-gaap_DerivativeNotionalAmount_bf9cb924-ce86-47f4-a41b-047636549f1f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_6a84f2cb-09f7-4111-b386-d2f1a1dbc24e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems_27ad224c-4383-4095-91fe-4a8b2cf05f9c" xlink:to="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_6a84f2cb-09f7-4111-b386-d2f1a1dbc24e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalanceSheetLocationAxis_2536ada3-2eb4-473d-9969-afa0751df6b4" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BalanceSheetLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_6a84f2cb-09f7-4111-b386-d2f1a1dbc24e" xlink:to="loc_us-gaap_BalanceSheetLocationAxis_2536ada3-2eb4-473d-9969-afa0751df6b4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_2536ada3-2eb4-473d-9969-afa0751df6b4_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BalanceSheetLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_2536ada3-2eb4-473d-9969-afa0751df6b4" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_2536ada3-2eb4-473d-9969-afa0751df6b4_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BalanceSheetLocationDomain_5ab6e82b-37d2-42e5-8d8d-05c4c85e0599" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BalanceSheetLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BalanceSheetLocationAxis_2536ada3-2eb4-473d-9969-afa0751df6b4" xlink:to="loc_us-gaap_BalanceSheetLocationDomain_5ab6e82b-37d2-42e5-8d8d-05c4c85e0599" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherCurrentAssetsMember_35c150a9-c87e-4291-aaab-e2ac8d78f8d2" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherCurrentAssetsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_5ab6e82b-37d2-42e5-8d8d-05c4c85e0599" xlink:to="loc_us-gaap_OtherCurrentAssetsMember_35c150a9-c87e-4291-aaab-e2ac8d78f8d2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherCurrentLiabilitiesMember_eb9a00cb-b178-43ab-9e53-34c023562bbe" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherCurrentLiabilitiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BalanceSheetLocationDomain_5ab6e82b-37d2-42e5-8d8d-05c4c85e0599" xlink:to="loc_us-gaap_OtherCurrentLiabilitiesMember_eb9a00cb-b178-43ab-9e53-34c023562bbe" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_f8285c33-49c0-4331-a268-57aaa66f840a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_6a84f2cb-09f7-4111-b386-d2f1a1dbc24e" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_f8285c33-49c0-4331-a268-57aaa66f840a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_f8285c33-49c0-4331-a268-57aaa66f840a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_f8285c33-49c0-4331-a268-57aaa66f840a" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_f8285c33-49c0-4331-a268-57aaa66f840a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_4e37cce5-25f1-4f73-8147-73e0fecc35e2" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_f8285c33-49c0-4331-a268-57aaa66f840a" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_4e37cce5-25f1-4f73-8147-73e0fecc35e2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignExchangeContractMember_3cf2af4e-bd10-4eb6-b020-bc1cf2d4d32c" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ForeignExchangeContractMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_4e37cce5-25f1-4f73-8147-73e0fecc35e2" xlink:to="loc_us-gaap_ForeignExchangeContractMember_3cf2af4e-bd10-4eb6-b020-bc1cf2d4d32c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CurrencySwapMember_6fb338a2-af82-45d5-bcc2-7b189c105e7d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CurrencySwapMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_4e37cce5-25f1-4f73-8147-73e0fecc35e2" xlink:to="loc_us-gaap_CurrencySwapMember_6fb338a2-af82-45d5-bcc2-7b189c105e7d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationAxis_2dda72df-5eaa-460f-8452-f6705aeb545d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_HedgingDesignationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable_6a84f2cb-09f7-4111-b386-d2f1a1dbc24e" xlink:to="loc_us-gaap_HedgingDesignationAxis_2dda72df-5eaa-460f-8452-f6705aeb545d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_2dda72df-5eaa-460f-8452-f6705aeb545d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_HedgingDesignationAxis_2dda72df-5eaa-460f-8452-f6705aeb545d" xlink:to="loc_us-gaap_HedgingDesignationDomain_2dda72df-5eaa-460f-8452-f6705aeb545d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_8d66c9f8-f3a4-429b-9603-cc9bd1285a5b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_HedgingDesignationAxis_2dda72df-5eaa-460f-8452-f6705aeb545d" xlink:to="loc_us-gaap_HedgingDesignationDomain_8d66c9f8-f3a4-429b-9603-cc9bd1285a5b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DesignatedAsHedgingInstrumentMember_2288023d-eaeb-4c1a-9c34-f1cf616c57c7" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DesignatedAsHedgingInstrumentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_8d66c9f8-f3a4-429b-9603-cc9bd1285a5b" xlink:to="loc_us-gaap_DesignatedAsHedgingInstrumentMember_2288023d-eaeb-4c1a-9c34-f1cf616c57c7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NondesignatedMember_66504cb2-54fb-472a-b1b0-fafef01ddd46" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NondesignatedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_8d66c9f8-f3a4-429b-9603-cc9bd1285a5b" xlink:to="loc_us-gaap_NondesignatedMember_66504cb2-54fb-472a-b1b0-fafef01ddd46" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/COMMITMENTSANDCONTINGENCIESDetails" xlink:type="simple" xlink:href="wab-20211231.xsd#COMMITMENTSANDCONTINGENCIESDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/COMMITMENTSANDCONTINGENCIESDetails" xlink:type="extended" id="i23037ac1618b4c3289838907cafe882a_COMMITMENTSANDCONTINGENCIESDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingenciesLineItems_62743986-d6a8-4ae7-8143-4d32cfd1f5b4" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LossContingenciesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyDamagesSoughtValue_cf77686d-7c7d-4064-97e4-6c3bd7284a76" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LossContingencyDamagesSoughtValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_62743986-d6a8-4ae7-8143-4d32cfd1f5b4" xlink:to="loc_us-gaap_LossContingencyDamagesSoughtValue_cf77686d-7c7d-4064-97e4-6c3bd7284a76" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyPendingClaimsNumber_8c766f3b-a08d-4373-8d93-72146f2d7754" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LossContingencyPendingClaimsNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingenciesLineItems_62743986-d6a8-4ae7-8143-4d32cfd1f5b4" xlink:to="loc_us-gaap_LossContingencyPendingClaimsNumber_8c766f3b-a08d-4373-8d93-72146f2d7754" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingenciesTable_69c5f87b-9907-4dd2-b8ec-75ed093727fc" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LossContingenciesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_LossContingenciesLineItems_62743986-d6a8-4ae7-8143-4d32cfd1f5b4" xlink:to="loc_us-gaap_LossContingenciesTable_69c5f87b-9907-4dd2-b8ec-75ed093727fc" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LitigationStatusAxis_99458040-9da8-418f-bc31-a2284c4bb764" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LitigationStatusAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_69c5f87b-9907-4dd2-b8ec-75ed093727fc" xlink:to="loc_us-gaap_LitigationStatusAxis_99458040-9da8-418f-bc31-a2284c4bb764" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LitigationStatusDomain_99458040-9da8-418f-bc31-a2284c4bb764_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LitigationStatusDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LitigationStatusAxis_99458040-9da8-418f-bc31-a2284c4bb764" xlink:to="loc_us-gaap_LitigationStatusDomain_99458040-9da8-418f-bc31-a2284c4bb764_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LitigationStatusDomain_4612b163-5b63-4420-989b-1bc22dbcc2b2" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LitigationStatusDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LitigationStatusAxis_99458040-9da8-418f-bc31-a2284c4bb764" xlink:to="loc_us-gaap_LitigationStatusDomain_4612b163-5b63-4420-989b-1bc22dbcc2b2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ThreatenedLitigationMember_c5c3367d-2b0f-4013-ae37-aa2f42a9897b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ThreatenedLitigationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LitigationStatusDomain_4612b163-5b63-4420-989b-1bc22dbcc2b2" xlink:to="loc_us-gaap_ThreatenedLitigationMember_c5c3367d-2b0f-4013-ae37-aa2f42a9897b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PendingLitigationMember_96911973-29b3-4643-886f-8bcd90d5f351" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PendingLitigationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LitigationStatusDomain_4612b163-5b63-4420-989b-1bc22dbcc2b2" xlink:to="loc_us-gaap_PendingLitigationMember_96911973-29b3-4643-886f-8bcd90d5f351" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_LitigationCaseAxis_c2d58855-30cd-4ee5-a4cb-45f7a01e7232" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_LitigationCaseAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_69c5f87b-9907-4dd2-b8ec-75ed093727fc" xlink:to="loc_srt_LitigationCaseAxis_c2d58855-30cd-4ee5-a4cb-45f7a01e7232" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_LitigationCaseTypeDomain_c2d58855-30cd-4ee5-a4cb-45f7a01e7232_default" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_LitigationCaseTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_LitigationCaseAxis_c2d58855-30cd-4ee5-a4cb-45f7a01e7232" xlink:to="loc_srt_LitigationCaseTypeDomain_c2d58855-30cd-4ee5-a4cb-45f7a01e7232_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_LitigationCaseTypeDomain_ed03afe0-3b36-46f6-825f-b0a32b21de03" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_LitigationCaseTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_LitigationCaseAxis_c2d58855-30cd-4ee5-a4cb-45f7a01e7232" xlink:to="loc_srt_LitigationCaseTypeDomain_ed03afe0-3b36-46f6-825f-b0a32b21de03" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_DenverTransitInstallationofConstantWirelessCrossingsMember_fdd886d6-4584-43b4-8d43-6fa482ea328f" xlink:href="wab-20211231.xsd#wab_DenverTransitInstallationofConstantWirelessCrossingsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_LitigationCaseTypeDomain_ed03afe0-3b36-46f6-825f-b0a32b21de03" xlink:to="loc_wab_DenverTransitInstallationofConstantWirelessCrossingsMember_fdd886d6-4584-43b4-8d43-6fa482ea328f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesAxis_7dadfa3b-35be-48d3-b6c1-80a94e8bd0ba" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_ConsolidatedEntitiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_LossContingenciesTable_69c5f87b-9907-4dd2-b8ec-75ed093727fc" xlink:to="loc_srt_ConsolidatedEntitiesAxis_7dadfa3b-35be-48d3-b6c1-80a94e8bd0ba" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_7dadfa3b-35be-48d3-b6c1-80a94e8bd0ba_default" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidatedEntitiesAxis_7dadfa3b-35be-48d3-b6c1-80a94e8bd0ba" xlink:to="loc_srt_ConsolidatedEntitiesDomain_7dadfa3b-35be-48d3-b6c1-80a94e8bd0ba_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_74c5755a-cb7e-4388-b0b2-c420266cc9ee" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidatedEntitiesAxis_7dadfa3b-35be-48d3-b6c1-80a94e8bd0ba" xlink:to="loc_srt_ConsolidatedEntitiesDomain_74c5755a-cb7e-4388-b0b2-c420266cc9ee" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SubsidiariesMember_089be332-9f1c-48f0-b0a5-4e885bd5b034" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_SubsidiariesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_74c5755a-cb7e-4388-b0b2-c420266cc9ee" xlink:to="loc_srt_SubsidiariesMember_089be332-9f1c-48f0-b0a5-4e885bd5b034" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/SEGMENTINFORMATIONSegmentFinancialInformationDetails" xlink:type="simple" xlink:href="wab-20211231.xsd#SEGMENTINFORMATIONSegmentFinancialInformationDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/SEGMENTINFORMATIONSegmentFinancialInformationDetails" xlink:type="extended" id="ide3bb8ffc9944bec972e3f9686d06c27_SEGMENTINFORMATIONSegmentFinancialInformationDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_2d34cfdb-5724-458c-8aaf-e5f9a75bc92a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SegmentReportingInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_24fe3b85-f977-471c-9815-2d42baeb5bbd" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_2d34cfdb-5724-458c-8aaf-e5f9a75bc92a" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_24fe3b85-f977-471c-9815-2d42baeb5bbd" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingIncomeLoss_ff1b4533-48b7-46a8-96d1-ccf8c2032903" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OperatingIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_2d34cfdb-5724-458c-8aaf-e5f9a75bc92a" xlink:to="loc_us-gaap_OperatingIncomeLoss_ff1b4533-48b7-46a8-96d1-ccf8c2032903" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_InterestExpenseAndOtherNet_cacd79f6-7722-44aa-b68f-3454e38fdfbd" xlink:href="wab-20211231.xsd#wab_InterestExpenseAndOtherNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_2d34cfdb-5724-458c-8aaf-e5f9a75bc92a" xlink:to="loc_wab_InterestExpenseAndOtherNet_cacd79f6-7722-44aa-b68f-3454e38fdfbd" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_76c02a6a-5065-434a-9a5a-171fa83859f2" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_2d34cfdb-5724-458c-8aaf-e5f9a75bc92a" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_76c02a6a-5065-434a-9a5a-171fa83859f2" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepreciationAndAmortization_11d4ed3e-901b-4562-852e-1d972b33f62f" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DepreciationAndAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_2d34cfdb-5724-458c-8aaf-e5f9a75bc92a" xlink:to="loc_us-gaap_DepreciationAndAmortization_11d4ed3e-901b-4562-852e-1d972b33f62f" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_a0329068-dc5c-4bc3-b10e-a67ff3a21dfd" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PaymentsToAcquirePropertyPlantAndEquipment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_2d34cfdb-5724-458c-8aaf-e5f9a75bc92a" xlink:to="loc_us-gaap_PaymentsToAcquirePropertyPlantAndEquipment_a0329068-dc5c-4bc3-b10e-a67ff3a21dfd" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Assets_382e9121-8944-4adc-8636-8701e512aa83" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_Assets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_2d34cfdb-5724-458c-8aaf-e5f9a75bc92a" xlink:to="loc_us-gaap_Assets_382e9121-8944-4adc-8636-8701e512aa83" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_f7a719bb-dfa0-4d48-a554-2c7d4f76f571" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_2d34cfdb-5724-458c-8aaf-e5f9a75bc92a" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_f7a719bb-dfa0-4d48-a554-2c7d4f76f571" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis_1cbf1c6f-0cc1-4a5f-849b-405701ba95ab" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_ConsolidationItemsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_f7a719bb-dfa0-4d48-a554-2c7d4f76f571" xlink:to="loc_srt_ConsolidationItemsAxis_1cbf1c6f-0cc1-4a5f-849b-405701ba95ab" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_1cbf1c6f-0cc1-4a5f-849b-405701ba95ab_default" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_1cbf1c6f-0cc1-4a5f-849b-405701ba95ab" xlink:to="loc_srt_ConsolidationItemsDomain_1cbf1c6f-0cc1-4a5f-849b-405701ba95ab_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_522e45e8-d7c1-4a17-9c3d-6aa25cd9f13b" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_1cbf1c6f-0cc1-4a5f-849b-405701ba95ab" xlink:to="loc_srt_ConsolidationItemsDomain_522e45e8-d7c1-4a17-9c3d-6aa25cd9f13b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingSegmentsMember_423f8bf2-4097-47b2-ab34-c7797f9b2194" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OperatingSegmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_522e45e8-d7c1-4a17-9c3d-6aa25cd9f13b" xlink:to="loc_us-gaap_OperatingSegmentsMember_423f8bf2-4097-47b2-ab34-c7797f9b2194" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_CorporateAndEliminationsMember_c9de05a6-34b3-4420-8dbb-c267393093da" xlink:href="wab-20211231.xsd#wab_CorporateAndEliminationsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_522e45e8-d7c1-4a17-9c3d-6aa25cd9f13b" xlink:to="loc_wab_CorporateAndEliminationsMember_c9de05a6-34b3-4420-8dbb-c267393093da" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_162032dc-e2e0-433d-9af6-cb0164e3bbd0" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_f7a719bb-dfa0-4d48-a554-2c7d4f76f571" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_162032dc-e2e0-433d-9af6-cb0164e3bbd0" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_162032dc-e2e0-433d-9af6-cb0164e3bbd0_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_162032dc-e2e0-433d-9af6-cb0164e3bbd0" xlink:to="loc_us-gaap_SegmentDomain_162032dc-e2e0-433d-9af6-cb0164e3bbd0_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_acd3fc23-5674-4f8e-914f-d617acffe39b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_162032dc-e2e0-433d-9af6-cb0164e3bbd0" xlink:to="loc_us-gaap_SegmentDomain_acd3fc23-5674-4f8e-914f-d617acffe39b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_FreightSegmentMember_36075705-1c1c-42c6-8588-1d1124cb9613" xlink:href="wab-20211231.xsd#wab_FreightSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_acd3fc23-5674-4f8e-914f-d617acffe39b" xlink:to="loc_wab_FreightSegmentMember_36075705-1c1c-42c6-8588-1d1124cb9613" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_TransitSegmentMember_16fe20ee-28f1-4ef0-8fc2-da32929c3aa3" xlink:href="wab-20211231.xsd#wab_TransitSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_acd3fc23-5674-4f8e-914f-d617acffe39b" xlink:to="loc_wab_TransitSegmentMember_16fe20ee-28f1-4ef0-8fc2-da32929c3aa3" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/SEGMENTINFORMATIONGeographicAreaDataDetails" xlink:type="simple" xlink:href="wab-20211231.xsd#SEGMENTINFORMATIONGeographicAreaDataDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/SEGMENTINFORMATIONGeographicAreaDataDetails" xlink:type="extended" id="i53b8b9ed8c204aabb95d42557917feef_SEGMENTINFORMATIONGeographicAreaDataDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_cb97b2bd-6235-4685-a78a-44ffcecd2053" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_f232d59d-79b6-4b56-b55f-632d1675eb7e" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_cb97b2bd-6235-4685-a78a-44ffcecd2053" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_f232d59d-79b6-4b56-b55f-632d1675eb7e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PropertyPlantAndEquipmentNet_69f9788c-5b21-4ce4-a729-2177903f57a7" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_cb97b2bd-6235-4685-a78a-44ffcecd2053" xlink:to="loc_us-gaap_PropertyPlantAndEquipmentNet_69f9788c-5b21-4ce4-a729-2177903f57a7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_5cc16ec2-109a-4c54-851e-e5cf549c0a40" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_RevenuesFromExternalCustomersAndLongLivedAssetsLineItems_cb97b2bd-6235-4685-a78a-44ffcecd2053" xlink:to="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_5cc16ec2-109a-4c54-851e-e5cf549c0a40" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis_182e57cf-725a-4029-9d60-584344d6335a" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_StatementGeographicalAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfRevenuesFromExternalCustomersAndLongLivedAssetsTable_5cc16ec2-109a-4c54-851e-e5cf549c0a40" xlink:to="loc_srt_StatementGeographicalAxis_182e57cf-725a-4029-9d60-584344d6335a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_182e57cf-725a-4029-9d60-584344d6335a_default" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_182e57cf-725a-4029-9d60-584344d6335a" xlink:to="loc_srt_SegmentGeographicalDomain_182e57cf-725a-4029-9d60-584344d6335a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_c22d7ce8-7d02-42b0-a722-71009d4ff170" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_182e57cf-725a-4029-9d60-584344d6335a" xlink:to="loc_srt_SegmentGeographicalDomain_c22d7ce8-7d02-42b0-a722-71009d4ff170" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_NorthAmericaMember_45898515-cb1a-46b2-8c49-b78ecb47d7fa" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_NorthAmericaMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_c22d7ce8-7d02-42b0-a722-71009d4ff170" xlink:to="loc_srt_NorthAmericaMember_45898515-cb1a-46b2-8c49-b78ecb47d7fa" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_US_5d398be5-8e74-48b3-b1f3-691caa056eab" xlink:href="https://xbrl.sec.gov/country/2021/country-2021.xsd#country_US"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NorthAmericaMember_45898515-cb1a-46b2-8c49-b78ecb47d7fa" xlink:to="loc_country_US_5d398be5-8e74-48b3-b1f3-691caa056eab" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_CA_c78aacb0-fc18-42f6-ab35-8e724bdb729b" xlink:href="https://xbrl.sec.gov/country/2021/country-2021.xsd#country_CA"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NorthAmericaMember_45898515-cb1a-46b2-8c49-b78ecb47d7fa" xlink:to="loc_country_CA_c78aacb0-fc18-42f6-ab35-8e724bdb729b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_MX_63c2b51c-47d6-4f69-bd90-2e09493b759d" xlink:href="https://xbrl.sec.gov/country/2021/country-2021.xsd#country_MX"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NorthAmericaMember_45898515-cb1a-46b2-8c49-b78ecb47d7fa" xlink:to="loc_country_MX_63c2b51c-47d6-4f69-bd90-2e09493b759d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SouthAmericaMember_b6752dc8-bceb-451d-910f-a1646aa9eed1" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_SouthAmericaMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_c22d7ce8-7d02-42b0-a722-71009d4ff170" xlink:to="loc_srt_SouthAmericaMember_b6752dc8-bceb-451d-910f-a1646aa9eed1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EuropeMember_5a2ad782-5f93-4633-a5d7-3e33838e7b7d" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_EuropeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_c22d7ce8-7d02-42b0-a722-71009d4ff170" xlink:to="loc_srt_EuropeMember_5a2ad782-5f93-4633-a5d7-3e33838e7b7d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_GB_35cfccf3-248b-4005-822d-92b12847b7b8" xlink:href="https://xbrl.sec.gov/country/2021/country-2021.xsd#country_GB"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EuropeMember_5a2ad782-5f93-4633-a5d7-3e33838e7b7d" xlink:to="loc_country_GB_35cfccf3-248b-4005-822d-92b12847b7b8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_DE_80d46f1d-a844-4ee1-88ca-1182bb8ce9f6" xlink:href="https://xbrl.sec.gov/country/2021/country-2021.xsd#country_DE"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EuropeMember_5a2ad782-5f93-4633-a5d7-3e33838e7b7d" xlink:to="loc_country_DE_80d46f1d-a844-4ee1-88ca-1182bb8ce9f6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_FR_08d7d301-9132-4ae9-8526-9d6058a43fe0" xlink:href="https://xbrl.sec.gov/country/2021/country-2021.xsd#country_FR"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EuropeMember_5a2ad782-5f93-4633-a5d7-3e33838e7b7d" xlink:to="loc_country_FR_08d7d301-9132-4ae9-8526-9d6058a43fe0" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_IT_7a2afc16-336e-4c9f-989b-2b82a541d57d" xlink:href="https://xbrl.sec.gov/country/2021/country-2021.xsd#country_IT"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EuropeMember_5a2ad782-5f93-4633-a5d7-3e33838e7b7d" xlink:to="loc_country_IT_7a2afc16-336e-4c9f-989b-2b82a541d57d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_CH_6fd1e8e7-bfea-4074-bea2-76b8a64f86f9" xlink:href="https://xbrl.sec.gov/country/2021/country-2021.xsd#country_CH"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EuropeMember_5a2ad782-5f93-4633-a5d7-3e33838e7b7d" xlink:to="loc_country_CH_6fd1e8e7-bfea-4074-bea2-76b8a64f86f9" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_OtherEuropeMember_267fdeea-6f9b-4612-ad40-34fcd103b3a6" xlink:href="wab-20211231.xsd#wab_OtherEuropeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EuropeMember_5a2ad782-5f93-4633-a5d7-3e33838e7b7d" xlink:to="loc_wab_OtherEuropeMember_267fdeea-6f9b-4612-ad40-34fcd103b3a6" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_IN_ea9d9d1a-5bcb-43a2-9abe-db51503cffaa" xlink:href="https://xbrl.sec.gov/country/2021/country-2021.xsd#country_IN"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_c22d7ce8-7d02-42b0-a722-71009d4ff170" xlink:to="loc_country_IN_ea9d9d1a-5bcb-43a2-9abe-db51503cffaa" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_AustraliaAndNewZealandMember_df434802-fc10-464e-bba3-a9c81a3ea5f1" xlink:href="wab-20211231.xsd#wab_AustraliaAndNewZealandMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_c22d7ce8-7d02-42b0-a722-71009d4ff170" xlink:to="loc_wab_AustraliaAndNewZealandMember_df434802-fc10-464e-bba3-a9c81a3ea5f1" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_CN_2c5b6793-d8a0-4a8f-ae78-c91f333de3d7" xlink:href="https://xbrl.sec.gov/country/2021/country-2021.xsd#country_CN"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_c22d7ce8-7d02-42b0-a722-71009d4ff170" xlink:to="loc_country_CN_2c5b6793-d8a0-4a8f-ae78-c91f333de3d7" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_OtherAsiaAndMiddleEastMember_038318f7-c26c-4fc0-ae36-ddfec028a5a7" xlink:href="wab-20211231.xsd#wab_OtherAsiaAndMiddleEastMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_c22d7ce8-7d02-42b0-a722-71009d4ff170" xlink:to="loc_wab_OtherAsiaAndMiddleEastMember_038318f7-c26c-4fc0-ae36-ddfec028a5a7" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_country_EG_95558896-bd0e-4396-a3ec-61608cf97cc5" xlink:href="https://xbrl.sec.gov/country/2021/country-2021.xsd#country_EG"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_c22d7ce8-7d02-42b0-a722-71009d4ff170" xlink:to="loc_country_EG_95558896-bd0e-4396-a3ec-61608cf97cc5" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_OtherAfricaMember_78340f5d-5ee2-4a1e-8493-98f0f5a329b0" xlink:href="wab-20211231.xsd#wab_OtherAfricaMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_c22d7ce8-7d02-42b0-a722-71009d4ff170" xlink:to="loc_wab_OtherAfricaMember_78340f5d-5ee2-4a1e-8493-98f0f5a329b0" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_RussiaAndCISMember_7ac94c17-6731-44ac-bebc-906d1498474a" xlink:href="wab-20211231.xsd#wab_RussiaAndCISMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_c22d7ce8-7d02-42b0-a722-71009d4ff170" xlink:to="loc_wab_RussiaAndCISMember_7ac94c17-6731-44ac-bebc-906d1498474a" xlink:type="arc" order="9"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/SEGMENTINFORMATIONSalesbyProductDetails" xlink:type="simple" xlink:href="wab-20211231.xsd#SEGMENTINFORMATIONSalesbyProductDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/SEGMENTINFORMATIONSalesbyProductDetails" xlink:type="extended" id="i9dbf3c2670104d7f82a8798bfc944dad_SEGMENTINFORMATIONSalesbyProductDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EntityWideInformationRevenueFromExternalCustomerLineItems_3085e93b-db13-4ba8-9c13-25ca2030003a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EntityWideInformationRevenueFromExternalCustomerLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_44a7ee51-3f2f-4087-8890-71b77ba97802" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EntityWideInformationRevenueFromExternalCustomerLineItems_3085e93b-db13-4ba8-9c13-25ca2030003a" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_44a7ee51-3f2f-4087-8890-71b77ba97802" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfEntityWideInformationRevenueFromExternalCustomersByProductsAndServicesTable_f89bc2c7-63b3-425b-adb0-3dff370120b9" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfEntityWideInformationRevenueFromExternalCustomersByProductsAndServicesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_EntityWideInformationRevenueFromExternalCustomerLineItems_3085e93b-db13-4ba8-9c13-25ca2030003a" xlink:to="loc_us-gaap_ScheduleOfEntityWideInformationRevenueFromExternalCustomersByProductsAndServicesTable_f89bc2c7-63b3-425b-adb0-3dff370120b9" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_5d6ac933-1df0-4d0a-b570-ff3f97a8e0e2" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEntityWideInformationRevenueFromExternalCustomersByProductsAndServicesTable_f89bc2c7-63b3-425b-adb0-3dff370120b9" xlink:to="loc_srt_ProductOrServiceAxis_5d6ac933-1df0-4d0a-b570-ff3f97a8e0e2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_5d6ac933-1df0-4d0a-b570-ff3f97a8e0e2_default" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_5d6ac933-1df0-4d0a-b570-ff3f97a8e0e2" xlink:to="loc_srt_ProductsAndServicesDomain_5d6ac933-1df0-4d0a-b570-ff3f97a8e0e2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_9f913a72-68f7-4e55-add2-09db21163dbf" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_5d6ac933-1df0-4d0a-b570-ff3f97a8e0e2" xlink:to="loc_srt_ProductsAndServicesDomain_9f913a72-68f7-4e55-add2-09db21163dbf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ServiceMember_fc486728-72ca-4678-bbb3-7b6b9503d98a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ServiceMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_9f913a72-68f7-4e55-add2-09db21163dbf" xlink:to="loc_us-gaap_ServiceMember_fc486728-72ca-4678-bbb3-7b6b9503d98a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquipmentMember_ee601b8f-b47d-4516-acb5-ab2e18312994" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EquipmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_9f913a72-68f7-4e55-add2-09db21163dbf" xlink:to="loc_us-gaap_EquipmentMember_ee601b8f-b47d-4516-acb5-ab2e18312994" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_ComponentsMember_c35bf04e-7f28-4760-94b8-843bad5d87db" xlink:href="wab-20211231.xsd#wab_ComponentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_9f913a72-68f7-4e55-add2-09db21163dbf" xlink:to="loc_wab_ComponentsMember_c35bf04e-7f28-4760-94b8-843bad5d87db" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_DigitalElectronicsMember_6e9e1328-9eee-42a2-90f3-0bdcaf387a01" xlink:href="wab-20211231.xsd#wab_DigitalElectronicsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_9f913a72-68f7-4e55-add2-09db21163dbf" xlink:to="loc_wab_DigitalElectronicsMember_6e9e1328-9eee-42a2-90f3-0bdcaf387a01" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_OEMMember_7684da11-dc32-427b-a679-1f9de7461f46" xlink:href="wab-20211231.xsd#wab_OEMMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_9f913a72-68f7-4e55-add2-09db21163dbf" xlink:to="loc_wab_OEMMember_7684da11-dc32-427b-a679-1f9de7461f46" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_AftermarketMember_c9c1988a-ce1c-418a-9046-731c1b3cb5f7" xlink:href="wab-20211231.xsd#wab_AftermarketMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_9f913a72-68f7-4e55-add2-09db21163dbf" xlink:to="loc_wab_AftermarketMember_c9c1988a-ce1c-418a-9046-731c1b3cb5f7" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_ed20c70e-f9f1-4e9b-98bd-27f113f176f2" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfEntityWideInformationRevenueFromExternalCustomersByProductsAndServicesTable_f89bc2c7-63b3-425b-adb0-3dff370120b9" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_ed20c70e-f9f1-4e9b-98bd-27f113f176f2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_ed20c70e-f9f1-4e9b-98bd-27f113f176f2_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_ed20c70e-f9f1-4e9b-98bd-27f113f176f2" xlink:to="loc_us-gaap_SegmentDomain_ed20c70e-f9f1-4e9b-98bd-27f113f176f2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_fb1eb95a-0d7f-40c9-9457-cc92bff028a0" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_ed20c70e-f9f1-4e9b-98bd-27f113f176f2" xlink:to="loc_us-gaap_SegmentDomain_fb1eb95a-0d7f-40c9-9457-cc92bff028a0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_FreightSegmentMember_7a60ca41-3895-4d06-ad3e-be377c636234" xlink:href="wab-20211231.xsd#wab_FreightSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_fb1eb95a-0d7f-40c9-9457-cc92bff028a0" xlink:to="loc_wab_FreightSegmentMember_7a60ca41-3895-4d06-ad3e-be377c636234" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_wab_TransitSegmentMember_b53aaad9-755f-4127-a519-2e2928d8d2ab" xlink:href="wab-20211231.xsd#wab_TransitSegmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_fb1eb95a-0d7f-40c9-9457-cc92bff028a0" xlink:to="loc_wab_TransitSegmentMember_b53aaad9-755f-4127-a519-2e2928d8d2ab" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://wabtec.com/role/SCHEDULEIIVALUATIONANDQUALIFYINGACCOUNTSDetails" xlink:type="simple" xlink:href="wab-20211231.xsd#SCHEDULEIIVALUATIONANDQUALIFYINGACCOUNTSDetails"/>
  <link:definitionLink xlink:role="http://wabtec.com/role/SCHEDULEIIVALUATIONANDQUALIFYINGACCOUNTSDetails" xlink:type="extended" id="i2eea4f6103c14952839c405720bdddfc_SCHEDULEIIVALUATIONANDQUALIFYINGACCOUNTSDetails">
    <link:loc xlink:type="locator" xlink:label="loc_srt_ValuationAndQualifyingAccountsDisclosureLineItems_e9e19e12-c2cb-4cce-a87b-287cf21431f6" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_ValuationAndQualifyingAccountsDisclosureLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MovementInValuationAllowancesAndReservesRollForward_25c54029-c389-4bc3-bbee-61050ed3ef96" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_MovementInValuationAllowancesAndReservesRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ValuationAndQualifyingAccountsDisclosureLineItems_e9e19e12-c2cb-4cce-a87b-287cf21431f6" xlink:to="loc_us-gaap_MovementInValuationAllowancesAndReservesRollForward_25c54029-c389-4bc3-bbee-61050ed3ef96" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesBalance_3810d3bf-3630-4f8d-b9ed-0c2edfc08aef" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ValuationAllowancesAndReservesBalance"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MovementInValuationAllowancesAndReservesRollForward_25c54029-c389-4bc3-bbee-61050ed3ef96" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesBalance_3810d3bf-3630-4f8d-b9ed-0c2edfc08aef" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense_7a9c624f-6223-44cc-8501-043e54b9f8f8" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MovementInValuationAllowancesAndReservesRollForward_25c54029-c389-4bc3-bbee-61050ed3ef96" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesChargedToCostAndExpense_7a9c624f-6223-44cc-8501-043e54b9f8f8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesChargedToOtherAccounts_b8a2f0e0-566d-41c1-8f19-90e6cd603c5b" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ValuationAllowancesAndReservesChargedToOtherAccounts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MovementInValuationAllowancesAndReservesRollForward_25c54029-c389-4bc3-bbee-61050ed3ef96" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesChargedToOtherAccounts_b8a2f0e0-566d-41c1-8f19-90e6cd603c5b" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesDeductions_e137ab56-41a4-468f-a7cf-84913cc01281" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ValuationAllowancesAndReservesDeductions"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_MovementInValuationAllowancesAndReservesRollForward_25c54029-c389-4bc3-bbee-61050ed3ef96" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesDeductions_e137ab56-41a4-468f-a7cf-84913cc01281" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesBalance_c28fc52c-1e59-4d7f-b25f-457f21d87969" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ValuationAllowancesAndReservesBalance"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ValuationAndQualifyingAccountsDisclosureTable_435c4e5e-0934-45cb-88d6-514e0e8b6038" xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_ValuationAndQualifyingAccountsDisclosureTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_srt_ValuationAndQualifyingAccountsDisclosureLineItems_e9e19e12-c2cb-4cce-a87b-287cf21431f6" xlink:to="loc_srt_ValuationAndQualifyingAccountsDisclosureTable_435c4e5e-0934-45cb-88d6-514e0e8b6038" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesTypeAxis_b137a79f-5b9a-4919-8722-838cc828678d" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ValuationAllowancesAndReservesTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_srt_ValuationAndQualifyingAccountsDisclosureTable_435c4e5e-0934-45cb-88d6-514e0e8b6038" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesTypeAxis_b137a79f-5b9a-4919-8722-838cc828678d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesDomain_b137a79f-5b9a-4919-8722-838cc828678d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ValuationAllowancesAndReservesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ValuationAllowancesAndReservesTypeAxis_b137a79f-5b9a-4919-8722-838cc828678d" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesDomain_b137a79f-5b9a-4919-8722-838cc828678d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationAllowancesAndReservesDomain_13eb9e1b-506e-47c3-a746-e5ebf861b58a" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ValuationAllowancesAndReservesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ValuationAllowancesAndReservesTypeAxis_b137a79f-5b9a-4919-8722-838cc828678d" xlink:to="loc_us-gaap_ValuationAllowancesAndReservesDomain_13eb9e1b-506e-47c3-a746-e5ebf861b58a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllowanceForCreditLossMember_da67689e-1d3e-4451-a19e-71af66090bfa" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AllowanceForCreditLossMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ValuationAllowancesAndReservesDomain_13eb9e1b-506e-47c3-a746-e5ebf861b58a" xlink:to="loc_us-gaap_AllowanceForCreditLossMember_da67689e-1d3e-4451-a19e-71af66090bfa" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ValuationAllowanceTaxCreditCarryforwardMember_4b3d3402-998c-46ad-9e9b-fa09d4e60380" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ValuationAllowanceTaxCreditCarryforwardMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ValuationAllowancesAndReservesDomain_13eb9e1b-506e-47c3-a746-e5ebf861b58a" xlink:to="loc_us-gaap_ValuationAllowanceTaxCreditCarryforwardMember_4b3d3402-998c-46ad-9e9b-fa09d4e60380" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://fasb.org/us-gaap/role/eedm/ExtensibleEnumerationLists" xlink:type="simple" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-roles-2021-01-31.xsd#eedm"/>
  <link:definitionLink xlink:role="http://fasb.org/us-gaap/role/eedm/ExtensibleEnumerationLists" xlink:type="extended">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LiabilitiesAbstract" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LiabilitiesAbstract"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherAccruedLiabilitiesCurrent" xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherAccruedLiabilitiesCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LiabilitiesAbstract" xlink:to="loc_us-gaap_OtherAccruedLiabilitiesCurrent" xlink:type="arc" order="0"/>
  </link:definitionLink>
</link:linkbase>
