winter sweet has 16 distinct synonyms spread across 4 of its 4 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.
dwarf aromatic shrub of Crete
aromatic Eurasian perennial
medium-sized shrubby tree of South Africa having thick leathery evergreen leaves and white or pink flowers and globose usually two-seeded purplish black fruits
deciduous Japanese shrub cultivated for its fragrant yellow flowers
Synonyms, antonyms and the broader and narrower relations for winter sweet come from Princeton University’s WordNet. Full sources and licences.