IDIOM // noun
1. a group of words established by usage as having a meaning not deducible from those of the individual words (e.g., rain cats and dogs, see the light sweatshop).
• a form of expression natural to a language, person, or group of people : he had a feeling for phrase and idiom.
• the dialect of a people or part of a country.
• the peculiar character or genius of a language.
2. a characteristic mode of expression in art : they were both working in a neo-Impressionist idiom.
• a distinct style or character, in music,
art, etc.: the idiom of Bach.