American English spelling vs US spelling

American English spelling and US spelling both are nouns.

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

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

American English spelling and US 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 English spelling.

American English spelling (noun)	US 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')