Animosity is a strong feeling of dislike or hostility toward someone. It's more intense than simple annoyance or disagreement. When there's animosity between two people, they harbor genuine ill will toward each other, often making it hard to work together or even be in the same room.

Animosity usually builds up over time. Two classmates might develop animosity after a series of arguments and hurt feelings, or two teams might feel animosity after several rough, competitive games. Sometimes animosity appears between groups, like when neighboring countries have a long history of conflict.

The word suggests something deeper and longer-lasting than temporary anger. If you get mad at your brother for breaking your favorite toy, that's anger. But if you hold onto that resentment for weeks, refusing to forgive him and looking for ways to hurt him back, that's animosity.

You might notice animosity in someone's tone of voice, their body language, or the way they speak about another person. When people feel animosity, they often struggle to say anything positive about each other. The feeling can be mutual (both people feel it) or one-sided (only one person harbors the animosity while the other remains friendly or indifferent).