smelt vs Osmerus mordax

smelt and Osmerus mordax both are nouns.

Word	Noun	Adjective	Verb	Adverb
smelt	Yes	No	Yes	No
Osmerus mordax	Yes	No	No	No

As nouns, Osmerus mordax is a hyponym of smelt; that is, Osmerus mordax is a word with a more specific, narrower meaning than smelt:

smelt: small trout-like silvery marine or freshwater food fishes of cold northern waters
Osmerus mordax: important marine and landlocked food fish of eastern North America and Alaska

Other hyponyms of smelt include rainbow smelt, European smelt, Osmerus eperlanus, sparling, capelan, capelin, caplin.

smelt (noun)	Osmerus mordax (noun)
small trout-like silvery marine or freshwater food fishes of cold northern waters	important marine and landlocked food fish of eastern North America and Alaska
small cold-water silvery fish; migrate between salt and fresh water

smelt (verb)	Osmerus mordax (verb)
extract (metals) by heating