os breve vs os

os breve and os both are nouns.

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

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

Other hypernyms of os breve include bone.

os breve (noun)	os (noun)
a bone that is of approximately equal dimension in all directions	rigid connective tissue that makes up the skeleton of vertebrates
	a mouth or mouthlike opening