| Noun | 1. | idiomatic expression - an expression whose meanings cannot be inferred from the meanings of the words that make it uplocution, saying, expression - a word or phrase that particular people use in particular situations; "pardon the expression" in the lurch - in a difficult or vulnerable position; "he resigned and left me in the lurch" like clockwork - with regularity and precision; "the rocket launch went off like clockwork" | |