wryneck has 1 distinct synonym spread across 1 of its 2 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.
an unnatural condition in which the head leans to one side because the neck muscles on that side are contracted
Old World woodpecker with a peculiar habit of twisting the neck
Synonyms, antonyms and the broader and narrower relations for wryneck come from Princeton University’s WordNet. Full sources and licences.