chorus has 4 distinct synonyms spread across 4 of its 7 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.
any utterance produced simultaneously by a group
“a chorus of boos”
a group of people assembled to sing together
a body of dancers or singers who perform together
a company of actors who comment (by speaking or singing in unison) on the action in a classical Greek play
utter in unison
“`yes,' the children chorused”
Synonyms, antonyms and the broader and narrower relations for chorus come from Princeton University’s WordNet. Full sources and licences.