dibranchiate vs cephalopod

dibranchiate and cephalopod both are nouns.

Word	Noun	Adjective	Verb	Adverb
dibranchiate	Yes	No	No	No
cephalopod	Yes	Yes	No	No

As nouns, cephalopod is a hypernym of dibranchiate; that is, cephalopod is a word with a broader meaning than dibranchiate:

dibranchiate: cephalopods having two gills
cephalopod: marine mollusk characterized by well-developed head and eyes and sucker-bearing tentacles

Other hypernyms of dibranchiate include cephalopod mollusk.

dibranchiate (noun)	cephalopod (noun)
cephalopods having two gills	marine mollusk characterized by well-developed head and eyes and sucker-bearing tentacles

dibranchiate (adjective)	cephalopod (adjective)
	relating or belonging to the class Cephalopoda