kingfish has 7 distinct synonyms spread across 3 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.
the lean flesh of any of several fish caught off the Atlantic coast of the United States
large edible mackerel of temperate United States coastal Atlantic waters
small silvery marine food fish found off California
any of several food and game fishes of the drum family indigenous to warm Atlantic waters of the North American coast
Synonyms, antonyms and the broader and narrower relations for kingfish come from Princeton University’s WordNet. Full sources and licences.