sport has 22 distinct synonyms spread across 7 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.
an active diversion requiring physical exertion and competition
the occupation of athletes who compete for pay
a person known for the way she (or he) behaves when teased or defeated or subjected to trying circumstances
“a good sport”
Synonyms, antonyms and the broader and narrower relations for sport come from Princeton University’s WordNet. Full sources and licences.