an amount of money that a person or business gets unexpectedly:
• Falling interest rates are a windfall for homeowners refinancing their mortgages.
• The group earned a windfall profit on the sale of part of an office building in Paris.
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windfall UK US /ˈwɪndfɔːl/ noun [C] FINANCE, TAX
► an amount of money that you receive unexpectedly: get/have/receive a windfall »
Investors each received a windfall of $5,000.
cash/financial/tax windfall »The investment firm unveiled a cash windfall for shareholders worth up to $650m.
windfall gains/profits »Staff stood to make substantial windfall gains from share options.
Financial and business terms. 2012.