n.

1. 惯用语；成语；习惯语[C]
   To pull one's leg is an idiom.

   “to pull one's leg”（同某人开玩笑）是惯用语。

2. 方言，土话；（个人特有）用语[C]
   He spoke in the idiom of the New England countryside.

   他讲新英格兰乡下的方言。

3. （某一）语言的习惯用法；（某一）语言的特性[U][C]
   She reads with a sharp eye for idiom.

   她阅读时以敏锐的目光审视语言的习惯用法。

4. （在音乐、美术等方面所表现的）风格，特色[C][U]
   the idiom of modern popular music

   现代通俗音乐的风格

n.

1. a group of words established by usage as having a meaning not deducible from those of the individual words (e.g. over the moon).
   ▸a form of expression natural to a language, person, or group.
2. a characteristic mode of expression in music or art.