What term describes phrases that have meanings different from their literal interpretations?

The term that describes phrases with meanings different from their literal interpretations is "idiom." Idioms are expressions whose meanings cannot be inferred from the individual words they comprise. For example, when someone says "it's raining cats and dogs," they are not stating that animals are falling from the sky; instead, they are conveying that it is raining heavily. This figurative language enriches communication by allowing speakers to express complex ideas or emotions in a concise manner.

In contrast, other choices such as metaphor refer to a direct comparison between two unlike things without using "like" or "as," and onomatopoeia involves words that phonetically imitate sounds associated with what they describe. Dramatic irony is a literary device where the audience knows more than the characters, creating tension or humor. While all of these terms relate to language and expression, idioms specifically capture the essence of phrases that defy literal interpretation.