axillary cavity vs axillary fossa

axillary cavity and axillary fossa both are nouns.

Word	Noun	Adjective	Verb	Adverb
axillary cavity	Yes	No	No	No
axillary fossa	Yes	No	No	No

As nouns, axillary cavity and axillary fossa are synonyms defined as:

axillary cavity and axillary fossa: the hollow under the arm where it is joined to the shoulder

Other synonyms of axillary cavity include armpit, axilla.

axillary cavity (noun)	axillary fossa (noun)
the hollow under the arm where it is joined to the shoulder	the hollow under the arm where it is joined to the shoulder