"Know what what" is not a word or a phrase that can have antonyms. It is unclear what the intended meaning behind this phrase is. However, if we take "know" as the main verb, its antonyms could be "ignore," "misunderstand," or "be unaware of." If we break down the phrase further and consider "what what" as two separate words, the antonyms for "what" could be "nothing," "nonentity," or "emptiness," while the antonyms for the second "what" could be "everything," "unlimited," or "abundance." Ultimately, it is vital to understand the intended meaning behind a word or phrase to identify their antonyms accurately.