/ˈɪdiəm / (say 'ideeuhm)

1. a form of expression peculiar to a language, especially one having a significance other than its literal one.
2. a variety or form of a language; a dialect.
3. the language peculiar to a people.
4. the peculiar character or genius of a language.
5. a distinct style or character, as in music, art, etc.: the idiom of Bach.
{Late Latin idiōma, from Greek idiōma, a peculiarity, originally, private property}

Australian English dictionary. 2014.

(sanctioned by use in any language) / (of a language), /