plume has 15 distinct synonyms spread across 5 of its 9 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.
be proud of
“He prides himself on making it into law school”
form a plume
“The chimneys were pluming the sky”
anything that resembles a feather in shape or lightness
“a plume of smoke”
the light horny waterproof structure forming the external covering of birds
Synonyms, antonyms and the broader and narrower relations for plume come from Princeton University’s WordNet. Full sources and licences.