nasal bone vs os

nasal bone and os both are nouns.

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

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

Other hypernyms of nasal bone include bone.

nasal bone (noun)	os (noun)
an elongated rectangular bone that forms the bridge of the nose	rigid connective tissue that makes up the skeleton of vertebrates
	a mouth or mouthlike opening