idiom

noun
1
a group of words whose meaning is different from the meanings of the individual words
اصطلاح
2
the kind of language and grammar used by particular people at a particular time or place
اصطلاح, سبک گفتاری
The friends would sometimes revert to playground idiom.
3
the style of writing, music, art, etc. that is typical of a particular person, group, period or place
سبک خاص, شیوه
the classical/contemporary/popular idiom
He has produced a classical play in a modern idiom.