unsex has 6 distinct synonyms spread across 1 of its 3 senses. Each sense below keeps its own list, because a synonym belongs to a meaning and not to a word: swapping one sense's substitute into another sense's sentence is how a thesaurus makes writing worse. WordNet records no antonym for it — antonymy is a relation between word forms rather than concepts, so it is deliberately sparse.
Counts are distinct word forms across every sense. A synonym that appears under three senses is counted once here and shown three times below, under each sense it belongs to.
remove the qualities typical of one's sex
“She unsexed herself”
make infertile
“in some countries, people with genetically transmissible disabilites are sterilized”
Synonyms, antonyms and the broader and narrower relations for unsex come from Princeton University’s WordNet. Full sources and licences.