sac vs enclosed space

sac and enclosed space both are nouns.

Word	Noun	Adjective	Verb	Adverb
sac	Yes	No	No	No
enclosed space	Yes	No	No	No

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

Other hypernyms of sac include cavity.

sac (noun)	enclosed space (noun)
a structure resembling a bag in an animal	space that is surrounded by something
a case or sheath especially a pollen sac or moss capsule
an enclosed space