os hyoideum vs os

os hyoideum and os both are nouns.

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

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

os hyoideum: a U-shaped bone at the base of the tongue that supports the tongue muscles
os: rigid connective tissue that makes up the skeleton of vertebrates

Other hypernyms of os hyoideum include bone.

os hyoideum (noun)	os (noun)
a U-shaped bone at the base of the tongue that supports the tongue muscles	rigid connective tissue that makes up the skeleton of vertebrates
	a mouth or mouthlike opening