- The definition of a windfall is something blown by wind, or unexpected good fortune.
- An example of a windfall is a tree that was uprooted in a hurricane.
- An example of a windfall is winning the lottery.
- something blown down by the wind, as fruit from a tree
- any unexpected acquisition, gain, or stroke of good luck
- A sudden, unexpected piece of good fortune or financial gain.
- Something, such as a ripened fruit, that has been blown down by the wind.
Of or relating to a windfall: windfall profits.