American spelling vs vitreous humor

American spelling and vitreous humor both are nouns.

Word	Noun	Adjective	Verb	Adverb
American spelling	Yes	No	No	No
vitreous humor	Yes	No	No	No

American spelling (noun)	vitreous humor (noun)
English orthography used in the United States (characterized by 'analyze', 'center', 'usable')	the clear colorless transparent jelly that fills the posterior chamber of the eyeball