temporal bone vs os

temporal bone and os both are nouns.

Word	Noun	Adjective	Verb	Adverb
temporal bone	Yes	No	No	No
os	Yes	No	No	No

As nouns, os is a hypernym of temporal bone; that is, os is a word with a broader meaning than temporal bone:

temporal bone: a thick bone forming the side of the human cranium and encasing the inner ear
os: rigid connective tissue that makes up the skeleton of vertebrates

Other hypernyms of temporal bone include bone.

temporal bone (noun)	os (noun)
a thick bone forming the side of the human cranium and encasing the inner ear	rigid connective tissue that makes up the skeleton of vertebrates
	a mouth or mouthlike opening