threadfin vs percoid

threadfin and percoid both are nouns.

Word	Noun	Adjective	Verb	Adverb
threadfin	Yes	No	No	No
percoid	Yes	No	No	No

As nouns, percoid is a hypernym of threadfin; that is, percoid is a word with a broader meaning than threadfin:

threadfin: mullet-like tropical marine fishes having pectoral fins with long threadlike rays
percoid: any of numerous spiny-finned fishes of the order Perciformes

Other hypernyms of threadfin include percoid fish, percoidean.

threadfin (noun)	percoid (noun)
mullet-like tropical marine fishes having pectoral fins with long threadlike rays	any of numerous spiny-finned fishes of the order Perciformes