bream has 2 distinct synonyms spread across 4 of its 5 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.
flesh of various freshwater fishes of North America or of Europe
flesh of any of various saltwater fishes of the family Sparidae or the family Bramidae
any of numerous marine percoid fishes especially (but not exclusively) of the family Sparidae
any of various usually edible freshwater percoid fishes having compressed bodies and shiny scales; especially (but not exclusively) of the genus Lepomis
Synonyms, antonyms and the broader and narrower relations for bream come from Princeton University’s WordNet. Full sources and licences.