king crab has 9 distinct synonyms spread across 4 of its 4 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.
meat of large cold-water crab; mainly leg meat
large edible crab of northern Pacific waters especially along the coasts of Alaska and Japan
large marine arthropod of the Atlantic coast of North America having a domed carapace that is shaped like a horseshoe and a stiff pointed tail; a living fossil related to the wood louse
Synonyms, antonyms and the broader and narrower relations for king crab come from Princeton University’s WordNet. Full sources and licences.