medieval vs American spelling

medieval is not a noun while American spelling is a noun.

Word	Noun	Adjective	Verb	Adverb
medieval	No	Yes	No	No
American spelling	Yes	No	No	No

medieval (noun)	American spelling (noun)
	English orthography used in the United States (characterized by 'analyze', 'center', 'usable')

medieval (adjective)	American spelling (adjective)
relating to or belonging to the Middle Ages
as if belonging to the Middle Ages; old-fashioned and unenlightened
characteristic of the time of chivalry and knighthood in the Middle Ages