To blow is to create a burst or puff of air. When chilly breezes start to blow, it's time to close your windows.
People blow candles out on birthday cakes and blow up balloons — a person blows by directing a flow of air from the mouth in a steady stream. When the wind blows, an air current moves. Another way to blow something is to burst, break, or ruin it: "If I drive over that broken glass, I'll blow a tire," or "I just know I'm going to blow my audition." You can also blow money, by wasting or squandering it.