When we talk about antonyms for the word "coin phrase", we need to consider the opposite meaning of each word. "Coin" is a verb that means creating or inventing something new, while "phrase" refers to a group of words expressing a single idea. Therefore, antonyms for "coin phrase" might include "borrowed expression", "repeated phrase", "commonplace language," or "stale idiom". These words imply that the phrase has a history, and it is not original. We use these antonyms in contexts where we want to emphasize unoriginality or lack of creativity. When we say something is a "borrowed expression," we mean it has been used many times before, and it is not innovative.