nerve center vs American spelling

nerve center and American spelling both are nouns.

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

nerve center (noun)	American spelling (noun)
a cluster of nerve cells governing a specific bodily process	English orthography used in the United States (characterized by 'analyze', 'center', 'usable')
a center that provides information and control