To defy means to refuse to obey or to openly resist something, often showing courage or determination. When a student defies a teacher's unfair rule, they're standing up against it despite potential consequences. A mountain climber defies gravity with every step upward. A small sailboat defies a storm when it battles through rough seas.

Defying something usually involves facing down authority, expectations, or natural limits. Sometimes defying makes sense: defying a bully who tells you not to be friends with someone. Sometimes it's reckless: defying your parents' safety rules. The word carries a sense of boldness, of refusing to back down even when something powerful opposes you.

You'll often see defy used with words like logic, explanation, or description. When something defies logic, it makes absolutely no sense. When a gymnast's flexibility defies belief, it seems almost impossible. When a skyscraper defies the laws of physics, it appears to accomplish something that should be impossible (though of course it doesn't actually break the laws of physics!).

The spirit of defying involves having the courage to resist when resistance matters, such as standing up for what is right or refusing to accept limits on what you can achieve.