hairless has no recorded synonym. 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. Its one recorded opposite is hairy.
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.
having no hair or fur
“a Mexican Hairless is about the size of a fox terrier and hairless except for a tufts on the head and tail”
Synonyms, antonyms and the broader and narrower relations for hairless come from Princeton University’s WordNet. Full sources and licences.