Anything blown down or off by the wind, as fruit from a tree, or the tree itself, or a portion of a forest prostrated by a violent wind, etc. Bacon. [1913 Webster]
An unexpected legacy, or other gain. [1913 Webster]
"He had a mighty windfall out of doubt." [1913 Webster]

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OXFORD DICTIONARY

windfall, n.
1 an apple or other fruit blown to the ground by the wind.
2 a piece of unexpected good fortune, esp. a legacy.

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THESAURUS

windfall

boast, bonus, buried treasure, catch, diamond, discovery, find, finding, foundling, gem, godsend, good thing, gravy, jewel, pearl, plum, pride, pride and joy, prize, treasure, treasure trove, trophy, trouvaille, trove, waifs, waifs and strays, windfall money, windfall profit, winner

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ROGET THESAURUS

windfall

Good

N good, benefit, advantage, improvement, greatest good, supreme good, interest, service, behoof, behalf, weal, main chance, summum bonum, common weal, consummation devoutly to be wished, gain, boot, profit, harvest, boon, good turn, blessing, world of good, piece of good luck, piece of good fortune, nuts, prize, windfall, godsend, waif, treasure-trove, good fortune, happiness, goodness, utility, remedy, pleasure giving, commendable, useful, good, beneficial, well, aright, satisfactorily, favorably, not amis, all for the best, to one's advantage, in one's favor, in one's interest, so far so good, magnum bonum.

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