American English spelling vs US English spelling

American English spelling and US English spelling both are nouns.

Word	Noun	Adjective	Verb	Adverb
American English spelling	Yes	No	No	No
US English spelling	Yes	No	No	No

As nouns, American English spelling and US English spelling are synonyms defined as:

American English spelling and US English spelling: English orthography used in the United States (characterized by 'analyze', 'center', 'usable')

Other synonyms of American English spelling include American English orthography, American spelling, US English orthography, US spelling.

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