appendicular skeleton vs pelvis

appendicular skeleton and pelvis both are nouns.

Word	Noun	Adjective	Verb	Adverb
appendicular skeleton	Yes	No	No	No
pelvis	Yes	No	No	No

appendicular skeleton (noun)	pelvis (noun)
the part of the skeleton that includes the pectoral girdle and the pelvic girdle and the upper and lower limbs	the structure of the vertebrate skeleton supporting the lower limbs in humans and the hind limbs or corresponding parts in other vertebrates
	a structure shaped like a funnel in the outlet of the kidney into which urine is discharged before passing into the ureter