American spelling vs stimulus generalization

American spelling and stimulus generalization both are nouns.

Word	Noun	Adjective	Verb	Adverb
American spelling	Yes	No	No	No
stimulus generalization	Yes	No	No	No

American spelling (noun)	stimulus generalization (noun)
English orthography used in the United States (characterized by 'analyze', 'center', 'usable')	(psychology) transfer of a response learned to one stimulus to a similar stimulus