Blow is a word with several different meanings:

1. To push air out of your mouth with force. You blow on hot soup to cool it down, blow out birthday candles, or blow a whistle. Wind blows when air moves across the land. A whale blows water and air out of its blowhole when it surfaces.
2. A hard hit or punch. A boxer lands a blow to an opponent's ribs. In stories, knights exchange blows with their swords. The phrase “come to blows” means people have started physically fighting. When something goes wrong, we call it a blow to our plans: “Losing the team's best player was a real blow to their championship hopes.”
3. To explode or burst suddenly. A tire can blow out on the highway. In older factories, a steam pipe might blow if the pressure got too high.

The word also appears in common phrases: to blow your top means to lose your temper, to blow someone's mind means to amaze them completely, and if something blows over, it means the problem or controversy fades away naturally, like storm clouds passing. If you blow a chance, you waste an opportunity through carelessness or poor judgment.