blue sage has 8 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.
sage of western North America to Central America having violet-blue flowers; widespread in cultivation
blue-flowered sage of dry prairies of the eastern United States
aromatic shrub of arid regions of western North America having hoary leaves
Synonyms, antonyms and the broader and narrower relations for blue sage come from Princeton University’s WordNet. Full sources and licences.