Pettiness is when someone focuses on small, unimportant things in a mean or spiteful way. When a person acts with pettiness, they make a big deal out of tiny slights or minor issues that most people would simply ignore or laugh off.

Imagine a classmate who refuses to share their markers with you because you once forgot to say “thank you” for borrowing a pencil. That's pettiness: letting a small oversight turn into ongoing resentment. Or picture someone who keeps track of every tiny mistake you make just so they can bring it up later to embarrass you. Pettiness often reveals itself in small acts of revenge or criticism that seem way out of proportion to what happened.

Being petty means letting small things consume your attention and energy. You might hear someone say “Don't be so petty” when a friend is complaining endlessly about something minor, like someone getting two more French fries than they did.