coelenteron vs sac

coelenteron and sac both are nouns.

Word	Noun	Adjective	Verb	Adverb
coelenteron	Yes	No	No	No
sac	Yes	No	No	No

As nouns, sac is a hypernym of coelenteron; that is, sac is a word with a broader meaning than coelenteron:

coelenteron (noun)	sac (noun)
the saclike body cavity of a coelenterate	a structure resembling a bag in an animal
	a case or sheath especially a pollen sac or moss capsule
	an enclosed space