What is the antonym of onomatopoeia?

There isn't a perfect antonym for onomatopoeia in the same way that there are for words like "hot" and "cold." However, depending on the context, these terms could be considered antonyms:

* Literal Language: This refers to language that uses words in their usual meanings, without any sound effects or imitations.

* Descriptive Language: While not the exact opposite, descriptive language focuses on describing a sound rather than mimicking it. For example, instead of "buzz," you might say "the sound of a bee's wings."

* Non-mimetic Language: This is a broad term for any language that doesn't imitate sounds.

Ultimately, the best "antonym" will depend on the specific situation and what you are trying to contrast with onomatopoeia.