To flout means to openly disobey or disregard a rule, law, or convention in a way that shows you don't care about it. When someone flouts the rules, they break them boldly and visibly, as if the rules don't matter.

If your school has a rule against running in the hallways and you sprint past the principal's office at full speed, you're flouting that rule. If a driver speeds through a red light right in front of a police officer, they're flouting traffic laws. The word suggests a kind of defiance or contempt: the person breaking the rule wants others to see them doing it, or doesn't care who notices.

Flouting is different from flaunting, which means showing something off proudly. You flaunt your new sneakers by wearing them where everyone can see them. You flout the dress code by wearing those sneakers on a day when they're not allowed. One word is about pride, the other about defiance.

When people say someone is flouting the rules, they usually mean it as serious criticism. The word carries a sense that the person isn't just making a mistake but deliberately showing disrespect.