An idiom is a phrase n which the words what?

An idiom is a phrase in which the words have a figurative meaning, meaning they don't mean what they literally say.

For example:

* "Kick the bucket" doesn't mean literally kicking a bucket, it means to die.

* "Break a leg" doesn't mean actually breaking your leg, it means good luck.

These phrases have meanings that are understood by native speakers of the language, but they don't make sense if you just look at the individual words.