WordWeb Online

1. A manner of speaking that is natural to native speakers of a language
   - parlance
    
2. The usage or vocabulary that is characteristic of a specific group of people
   "the immigrants spoke an odd idiom of English";
   - dialect, accent
    
3. The style of a particular artist, school or movement
   "an imaginative orchestral idiom";
   - artistic style
    
4. An expression whose meanings cannot be inferred from the meanings of the words that make it up
   - idiomatic expression, phrasal idiom, set phrase, phrase

Derived forms: idioms

Type of: expression, fashion, formulation, locution, manner, mode, non-standard speech, saying, style, way

Encyclopedia: Idiom