dusty miller has 15 distinct synonyms spread across 5 of its 5 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.
shrubby perennial of the Canary Islands having white flowers and leaves and hairy stems covered with dustlike down; sometimes placed in genus Chrysanthemum
stiff much-branched perennial of the Mediterranean region having very white woolly stems and leaves
a plant having leaves and stems covered with down that resembles dust
herb with greyish leaves found along the east coast of North America; used as an ornamental plant
an old cottage garden plant of southeastern Europe widely cultivated for its attractive white woolly foliage and showy crimson flowers
Synonyms, antonyms and the broader and narrower relations for dusty miller come from Princeton University’s WordNet. Full sources and licences.