ventricle vs cavum

ventricle and cavum both are nouns.

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

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

ventricle: one of four connected cavities in the brain; is continuous with the central canal of the spinal cord and contains cerebrospinal fluid
cavum: (anatomy) a natural hollow or sinus within the body

Other hypernyms of ventricle include bodily cavity, cavity.

ventricle (noun)	cavum (noun)
a chamber of the heart that receives blood from an atrium and pumps it to the arteries	(anatomy) a natural hollow or sinus within the body
one of four connected cavities in the brain; is continuous with the central canal of the spinal cord and contains cerebrospinal fluid