pollack vs gadoid fish

pollack and gadoid fish both are nouns.

Word	Noun	Adjective	Verb	Adverb
pollack	Yes	No	No	No
gadoid fish	Yes	No	No	No

As nouns, gadoid fish is a hypernym of pollack; that is, gadoid fish is a word with a broader meaning than pollack:

pollack: important food and game fish of northern seas (especially the northern Atlantic); related to cod
gadoid fish: a soft-finned fish of the family Gadidae

Other hypernyms of pollack include gadoid.

pollack (noun)	gadoid fish (noun)
important food and game fish of northern seas (especially the northern Atlantic); related to cod	a soft-finned fish of the family Gadidae
lean white flesh of North Atlantic fish; similar to codfish