gadoid fish vs cod

gadoid fish and cod both are nouns.

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

As nouns, cod is a hyponym of gadoid fish; that is, cod is a word with a more specific, narrower meaning than gadoid fish:

gadoid fish (noun)	cod (noun)
a soft-finned fish of the family Gadidae	major food fish of Arctic and cold-temperate waters
	lean white flesh of important North Atlantic food fish; usually baked or poached
	the vessel that contains the seeds of a plant (not the seeds themselves)

gadoid fish (adjective)	cod (adjective)
	payable by the recipient on delivery

gadoid fish (verb)	cod (verb)
	harass with persistent criticism or carping
	fool or hoax