pelvic girdle vs pubic bone

pelvic girdle and pubic bone both are nouns.

Word	Noun	Adjective	Verb	Adverb
pelvic girdle	Yes	No	No	No
pubic bone	Yes	No	No	No

pelvic girdle (noun)	pubic bone (noun)
the structure of the vertebrate skeleton supporting the lower limbs in humans and the hind limbs or corresponding parts in other vertebrates	one of the three sections of the hipbone; together these two bones form the front of the pelvis