American spelling vs dead center

American spelling and dead center both are nouns.

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

American spelling (noun)	dead center (noun)
English orthography used in the United States (characterized by 'analyze', 'center', 'usable')	the position of a crank when it is in line with the connecting rod and not exerting torque