old man's beard has 10 distinct synonyms spread across 3 of its 3 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.
dense festoons of greenish-grey hairlike flexuous strands anchored to tree trunks and branches by sparse wiry roots; southeastern United States and West Indies to South America
vigorous deciduous climber of Europe to Afghanistan and Lebanon having panicles of fragrant green-white flowers in summer and autumn
common climber of eastern North America that sprawls over other plants and bears numerous panicles of small creamy white flowers
Synonyms, antonyms and the broader and narrower relations for old man's beard come from Princeton University’s WordNet. Full sources and licences.