cotyloid cavity vs acetabulum

cotyloid cavity and acetabulum both are nouns.

Word	Noun	Adjective	Verb	Adverb
cotyloid cavity	Yes	No	No	No
acetabulum	Yes	No	No	No

As nouns, cotyloid cavity and acetabulum are synonyms defined as:

cotyloid cavity and acetabulum: the cup-shaped hollow in the hipbone into which the head of the femur fits to form a ball-and-socket joint

cotyloid cavity (noun)	acetabulum (noun)
the cup-shaped hollow in the hipbone into which the head of the femur fits to form a ball-and-socket joint	the cup-shaped hollow in the hipbone into which the head of the femur fits to form a ball-and-socket joint