windfall
An unexpected amount of money or good luck you receive.
A windfall is an unexpected piece of good fortune, especially money or profit that arrives without much effort.
Today, when someone receives a windfall, they might inherit money from a distant relative they barely knew, find a valuable baseball card in their attic worth thousands of dollars, or win a prize in a contest they forgot they entered. A company might experience a windfall when a product unexpectedly becomes hugely popular.
The word carries a sense of pleasant surprise. It's different from something you worked and planned for: a windfall just happens to you. If you spend months training for a competition and win the prize money, that's not a windfall. That's earned success. But if your grandmother unexpectedly gives you $50 for your birthday when you were expecting just a card, that is a windfall.
Some windfalls are small, like finding a $20 bill in an old coat pocket. Others are enormous, like winning the lottery. Either way, the core meaning stays the same: good fortune that drops into your lap, like apples tumbling from a tree in a storm.