Usage examples "idiom":
This being so, the more tap- roots a language sends down into the soil of life, and the more varied the strata of human experience from which it draws its nourishment, whether of vocabulary or idiom,
the more perfect will be its potentialities as a medium of expression. - "America To-day, Observations and Reflections",
While seeming to speak like everyone else, the mystic uses a personal idiom:
things becoming symbols at the pleasure of his fancy, he does not use signs that have a fixed and universally admitted value. - "Essay on the Creative Imagination",
Sometimes this incompleteness is justified by the idiom
of the language, but more often it is the result of carelessness on the part of the speaker. - "Composition-Rhetoric",
Stratton D. Brooks.