pelvic girdle vs appendicular skeleton

pelvic girdle and appendicular skeleton both are nouns.

Word	Noun	Adjective	Verb	Adverb
pelvic girdle	Yes	No	No	No
appendicular skeleton	Yes	No	No	No

pelvic girdle (noun)	appendicular skeleton (noun)
the structure of the vertebrate skeleton supporting the lower limbs in humans and the hind limbs or corresponding parts in other vertebrates	the part of the skeleton that includes the pectoral girdle and the pelvic girdle and the upper and lower limbs