os vs bone

os and bone both are nouns.

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

As nouns, os and bone are synonyms defined as:

os and bone: rigid connective tissue that makes up the skeleton of vertebrates

os (noun)	bone (noun)
rigid connective tissue that makes up the skeleton of vertebrates	a shade of white the color of bleached bones
a mouth or mouthlike opening	rigid connective tissue that makes up the skeleton of vertebrates
	the porous calcified substance from which bones are made

os (adjective)	bone (adjective)
	consisting of or made up of bone

os (verb)	bone (verb)
	remove the bones from
	study intensively, as before an exam