parlance, idiom -- (a manner of speaking that is natural to native speakers of a language)
dialect, idiom, 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")
artistic style, idiom -- (the style of a particular artist or school or movement; "an imaginative orchestral idiom")