eelpout has 5 distinct synonyms spread across 2 of its 2 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.
marine eellike mostly bottom-dwelling fishes of northern seas
elongate freshwater cod of northern Europe and Asia and North America having barbels around its mouth
Synonyms, antonyms and the broader and narrower relations for eelpout come from Princeton University’s WordNet. Full sources and licences.