All 5 Uses

idiom
in
Politics and the English Language
(Auto-generated)

—PROFESSOR HAROLD LASKI (Essay in FREEDOM OF EXPRESSION) (2) Above all, we cannot play ducks and drakes with a native battery of idioms which prescribes such egregious collocations of vocables as the Basic PUT UP WITH for TOLERATE or PUT AT A LOSS for BEWILDER.†
By using stale metaphors, similes and idioms, you save much mental effort at the cost of leaving your meaning vague, not only for your reader but for yourself.†
What image or idiom will make it clearer?†
*
When there is a gap between one's real and one's declared aims, one turns, as it were instinctively, to long words and exhausted idioms, like a cuttlefish squirting out ink.†
On the contrary, it is especially concerned with the scrapping of every word or idiom which has outworn its usefulness.†

Definitions:

(1) (idiom)
a way of putting things that is characteristic of a specific group of people

An idiom typically refers to an expression whose meaning cannot be inferred from the meanings of the words that make it up (as in "feeling under the weather"). It can also refer to a particular artistic style.
(2) (meaning too rare to warrant focus)