1.NounSomething that has been blown down by the wind.
2.NounThe act of something being blown down by wind.
3.NounA fruit that has fallen from a tree naturally, as from wind.
"They couldn't reach the branches, so they ate the windfalls."
4.NounA sudden large benefit; especially, a sudden or unexpected large amount of money, as from lottery or sweepstakes winnings or an unexpected inheritance or gift.