American spelling vs skeptical

American spelling is a noun but skeptical is not a noun.

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

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

American spelling (adjective)	skeptical (adjective)
	marked by or given to doubt
	denying or questioning the tenets of especially a religion