renal pelvis vs bodily cavity

renal pelvis and bodily cavity both are nouns.

Word	Noun	Adjective	Verb	Adverb
renal pelvis	Yes	No	No	No
bodily cavity	Yes	No	No	No

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

renal pelvis: a structure shaped like a funnel in the outlet of the kidney into which urine is discharged before passing into the ureter
bodily cavity: (anatomy) a natural hollow or sinus within the body

Other hypernyms of renal pelvis include cavity, cavum.

renal pelvis (noun)	bodily cavity (noun)
a structure shaped like a funnel in the outlet of the kidney into which urine is discharged before passing into the ureter	(anatomy) a natural hollow or sinus within the body