fever tree has 6 distinct synonyms spread across 3 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.
any of several trees having leaves or bark used to allay fever or thought to indicate regions free of fever
ornamental shrub or small tree of swampy areas in southwestern United States having large pink or white sepals and yielding Georgia bark for treating fever
Synonyms, antonyms and the broader and narrower relations for fever tree come from Princeton University’s WordNet. Full sources and licences.
tall fast-growing timber tree with leaves containing a medicinal oil; young leaves are bluish