frost fish vs percoidean

frost fish and percoidean both are nouns.

Word	Noun	Adjective	Verb	Adverb
frost fish	Yes	No	No	No
percoidean	Yes	No	No	No

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

frost fish: long-bodied marine fishes having a long whiplike scaleless body and sharp teeth; closely related to snake mackerel
percoidean: any of numerous spiny-finned fishes of the order Perciformes

Other hypernyms of frost fish include percoid, percoid fish.

frost fish (noun)	percoidean (noun)
long-bodied marine fishes having a long whiplike scaleless body and sharp teeth; closely related to snake mackerel	any of numerous spiny-finned fishes of the order Perciformes