yam bean has 3 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.
twining plant of Amazon basin having large edible roots
Central American twining plant with edible roots and pods; large tubers are eaten raw or cooked especially when young and young pods must be thoroughly cooked; pods and seeds also yield rotenone and oils
Synonyms, antonyms and the broader and narrower relations for yam bean come from Princeton University’s WordNet. Full sources and licences.