sinus vs bodily cavity

sinus and bodily cavity both are nouns.

Word	Noun	Adjective	Verb	Adverb
sinus	Yes	No	No	No
bodily cavity	Yes	No	No	No

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

sinus: any of various air-filled cavities especially in the bones of the skull
bodily cavity: (anatomy) a natural hollow or sinus within the body

Other hypernyms of sinus include cavity, cavum.

sinus (noun)	bodily cavity (noun)
a wide channel containing blood; does not have the coating of an ordinary blood vessel	(anatomy) a natural hollow or sinus within the body
any of various air-filled cavities especially in the bones of the skull
an abnormal passage leading from a suppurating cavity to the body surface