An idiom (also called idiomatic expression) is an expression, word, or phrase that has a figurative meaning conventionally understood by native speakers.This meaning is different from the literal meaning of the idiom's individual elements. In other words, idioms don't mean exactly what the words say.They have, however, hidden meaning. Examples Kick the bucket Spill the beans. The meaning of these expressions is different from the literal meaning or definition of the words of which they are made.Their meaning are however used figuratively.n other words, idioms don't mean exactly what the words say. They have, however, hidden meaning. Examples Kick the bucket Spill the beans. The meaning of these expressions is different from the literal meaning or definition of the words of which they are made. Their meaning are however used figuratively.