The butt of something is its thickest or bottom end. The butt of a rifle rests against your shoulder when you aim. The butt of a fishing rod is the thick end you hold. A cigarette butt is what's left after someone finishes smoking it.

Your butt is also the part of your body you sit on, more formally called your buttocks or rear end. When you plop down in a chair, you're sitting on your butt.

The word appears in several common expressions. If you're the butt of a joke, you're the person everyone's laughing at, not with. When something is placed butt to butt, the two thick or bottom ends are touching. And when someone tells you to get your butt in gear, they're saying to hurry up and get moving.

As a verb, butt can mean to push or strike with your head, like when a goat butts someone with its horns.