scarlet runner has 8 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.
tropical American bean with red flowers and mottled black beans similar to Phaseolus vulgaris but perennial; a preferred food bean in Great Britain
hairy trailing or prostrate western Australian vine with bright scarlet-pink flowers
long bean pods usually sliced into half-inch lengths; a favorite in Britain
Synonyms, antonyms and the broader and narrower relations for scarlet runner come from Princeton University’s WordNet. Full sources and licences.