Depending on the context:
* Pragmatics: This focuses on the meaning of words in context, considering the speaker's intentions and the effect on the listener, whereas semantics focuses on the literal meaning of words.
* Syntax: While semantics deals with meaning, syntax deals with the grammatical structure of language.
* Phonetics/Phonology: These deal with the sounds of language, while semantics deals with the meaning of words.
* Non-literal: If semantics is about the literal meaning, the antonym could be "non-literal," "figurative," or "metaphorical."
* Meaningless: If semantics is about meaning, the antonym could be "meaningless," "nonsensical," or "unintelligible."
It's important to consider the specific context in which you are using "semantics" to choose the most appropriate antonym.