marrow vs os

marrow and os both are nouns.

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

marrow (noun)	os (noun)
the fatty network of connective tissue that fills the cavities of bones	rigid connective tissue that makes up the skeleton of vertebrates
the choicest or most essential or most vital part of some idea or experience	a mouth or mouthlike opening
large elongated squash with creamy to deep green skins
very tender and very nutritious tissue from marrowbones
any of various squash plants grown for their elongated fruit with smooth dark green skin and whitish flesh