butterfly plant has 4 distinct synonyms spread across 2 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.
orchid having large elliptic to obovate fleshy leaves and fragrant pink-and-white flowers dotted with red
any orchid of the genus Oncidium: characterized by slender branching sprays of small yellow and brown flowers; often grown as houseplants
Synonyms, antonyms and the broader and narrower relations for butterfly plant come from Princeton University’s WordNet. Full sources and licences.