lip has 7 distinct synonyms spread across 2 of its 5 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.
either of two fleshy folds of tissue that surround the mouth and play a role in speaking
(botany) either of the two parts of a bilabiate corolla or calyx
Synonyms, antonyms and the broader and narrower relations for lip come from Princeton University’s WordNet. Full sources and licences.
either the outer margin or the inner margin of the aperture of a gastropod's shell