smelt vs European smelt

smelt and European smelt both are nouns.

Word	Noun	Adjective	Verb	Adverb
smelt	Yes	No	Yes	No
European smelt	Yes	No	No	No

As nouns, European smelt is a hyponym of smelt; that is, European smelt 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
European smelt: the common smelt of Europe

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

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

Other hyponyms of smelt include American smelt, rainbow smelt, sparling.

smelt (noun)	European smelt (noun)
small trout-like silvery marine or freshwater food fishes of cold northern waters	the common smelt of Europe
small cold-water silvery fish; migrate between salt and fresh water	common smelt of Europe

smelt (verb)	European smelt (verb)
extract (metals) by heating