When you mitigate something harmful or unpleasant, you make it less severe, less painful, or less damaging.

A doctor might prescribe medicine to mitigate the pain of an injury. A city plants trees along highways to mitigate noise pollution for nearby neighborhoods. After you accidentally offend your friend, apologizing quickly can mitigate the hurt feelings. If your team loses a game badly, finding something positive to focus on, like one player's improvement, helps mitigate the disappointment.

Mitigating doesn't eliminate a problem completely: it reduces the impact. Wearing a helmet doesn't prevent bicycle accidents, but it mitigates the risk of serious head injury. Studying the night before a test won't guarantee an A, but it will mitigate the chances of failing.

The related noun mitigation describes the act of making something less bad. Climate scientists talk about mitigation strategies to reduce greenhouse gas emissions. Lawyers argue for mitigation of punishment by explaining circumstances that make a crime less serious.