furcula vs os

furcula and os both are nouns.

Word	Noun	Adjective	Verb	Adverb
furcula	Yes	No	No	No
os	Yes	No	No	No

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

Other hypernyms of furcula include bone.

furcula (noun)	os (noun)
a forked bone formed by the fusion of the clavicles of most birds	rigid connective tissue that makes up the skeleton of vertebrates
	a mouth or mouthlike opening