call center vs American spelling

call center and American spelling both are nouns.

Word	Noun	Adjective	Verb	Adverb
call center	Yes	No	No	No
American spelling	Yes	No	No	No

call center (noun)	American spelling (noun)
a center equipped to handle a large volume of telephone calls (especially for taking orders or serving customers)	English orthography used in the United States (characterized by 'analyze', 'center', 'usable')