an amount of money that you win or receive from someone unexpectedly

Investors each received a windfall of £3,000. 投资者每人都获得了3000英镑的意外之财。

UK The government is hoping to collect a windfall tax (= extra tax on a large unexpected company profit) from British Electric. 政府打算针对英国电气公司获得的大笔意外利润征收额外的税款。

a piece of fruit blown down from a tree

I tend to leave the windfalls for the birds to pick at. 我常常会把被风吹落的水果留给鸟儿们啄食。