pelvic cavity vs cavity

pelvic cavity and cavity both are nouns.

Word	Noun	Adjective	Verb	Adverb
pelvic cavity	Yes	No	No	No
cavity	Yes	No	No	No

As nouns, cavity is a hypernym of pelvic cavity; that is, cavity is a word with a broader meaning than pelvic cavity:

pelvic cavity: the space bounded by the bones of the pelvis and containing the pelvic viscera
cavity: (anatomy) a natural hollow or sinus within the body

Other hypernyms of pelvic cavity include bodily cavity, cavum.

pelvic cavity (noun)	cavity (noun)
the space bounded by the bones of the pelvis and containing the pelvic viscera	(anatomy) a natural hollow or sinus within the body
	a sizeable hole (usually in the ground)
	soft decayed area in a tooth; progressive decay can lead to the death of a tooth
	space that is surrounded by something