cephalopod mollusk vs cephalopod

cephalopod mollusk and cephalopod both are nouns.

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

As nouns, cephalopod mollusk and cephalopod are synonyms defined as:

cephalopod mollusk and cephalopod: marine mollusk characterized by well-developed head and eyes and sucker-bearing tentacles

cephalopod mollusk (noun)	cephalopod (noun)
marine mollusk characterized by well-developed head and eyes and sucker-bearing tentacles	marine mollusk characterized by well-developed head and eyes and sucker-bearing tentacles

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