abdomen vs cavum

abdomen and cavum both are nouns.

Word	Noun	Adjective	Verb	Adverb
abdomen	Yes	No	No	No
cavum	Yes	No	No	No

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

abdomen: the cavity containing the major viscera; in mammals it is separated from the thorax by the diaphragm
cavum: (anatomy) a natural hollow or sinus within the body

Other hypernyms of abdomen include bodily cavity, cavity.

abdomen (noun)	cavum (noun)
the region of the body of a vertebrate between the thorax and the pelvis	(anatomy) a natural hollow or sinus within the body
the cavity containing the major viscera; in mammals it is separated from the thorax by the diaphragm