ratable vs American spelling

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

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

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

ratable (adjective)	American spelling (adjective)
liable to payment of locally assessed property taxes