When you're resentful, you feel bitter and angry about something you think is unfair, and that feeling sticks with you. If your sister gets a new bike while you have to keep riding your old one, you might feel resentful every time you see her riding past. If a friend breaks a promise and never apologizes, you might carry resentful feelings for weeks or even months.

Resentment is the noun form: the actual feeling of bitterness you hold onto. What makes resentment different from regular anger is how it lingers. You might get angry when someone cuts in front of you in line, but that anger fades quickly. Resentment settles in and stays, coloring how you see that person or situation. A student might feel resentful toward a teacher they believe graded them unfairly, and that feeling might last the whole school year.

Resentment builds when people feel powerless to change something they see as unjust. A younger sibling might resent always having an earlier bedtime, or a player might resent sitting on the bench while others play. The feeling comes from thinking “this isn't fair” and not being able to do anything about it. Resentment can poison relationships and make you unhappy, even when the original unfairness was small.