definition of
idiom

[1] #1 idiom n. [parlance] a manner of speaking that is natural to native speakers of a language. wn

[2] #2 idiom n. [dialect, accent] the usage or vocabulary that is characteristic of a specific group of people; "the immigrants spoke an odd dialect of English"; "he has a strong German accent"; "it has been said that a language is a dialect with an army and navy". wn

[3] #3 idiom n. [artistic style] the style of a particular artist or school or movement; "an imaginative orchestral idiom". wn

[4] #4 idiom n. [idiomatic expression, phrasal idiom, set phrase, phrase] an expression whose meanings cannot be inferred from the meanings of the words that make it up. wn