rattail fish vs gadoid

rattail fish and gadoid both are nouns.

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

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

rattail fish: deep-sea fish with a large head and body and long tapering tail
gadoid: a soft-finned fish of the family Gadidae

Other hypernyms of rattail fish include gadoid fish.

rattail fish (noun)	gadoid (noun)
deep-sea fish with a large head and body and long tapering tail	a soft-finned fish of the family Gadidae