greater peritoneal sac vs cavum

greater peritoneal sac and cavum both are nouns.

Word	Noun	Adjective	Verb	Adverb
greater peritoneal sac	Yes	No	No	No
cavum	Yes	No	No	No

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

greater peritoneal sac: the interior of the peritoneum; a potential space between layers of the peritoneum
cavum: (anatomy) a natural hollow or sinus within the body

Other hypernyms of greater peritoneal sac include bodily cavity, cavity.

greater peritoneal sac (noun)	cavum (noun)
the interior of the peritoneum; a potential space between layers of the peritoneum	(anatomy) a natural hollow or sinus within the body