nerium oleander has 2 distinct synonyms spread across 1 of its 1 sense. 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 ornamental but poisonous flowering shrub having narrow evergreen leaves and clusters of fragrant white to pink or red flowers: native to East Indies but widely cultivated in warm regions
Synonyms, antonyms and the broader and narrower relations for nerium oleander come from Princeton University’s WordNet. Full sources and licences.