skepticism vs American spelling

skepticism and American spelling both are nouns.

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

skepticism (noun)	American spelling (noun)
doubt about the truth of something	English orthography used in the United States (characterized by 'analyze', 'center', 'usable')
the disbelief in any claims of ultimate knowledge