alienage vs alienism

alienage and alienism both are nouns.

Word	Noun	Adjective	Verb	Adverb
alienage	Yes	No	No	No
alienism	Yes	No	No	No

As nouns, alienage and alienism are synonyms defined as:

alienage (noun)	alienism (noun)
the quality of being alien	the quality of being alien
	an obsolete term for the study and treatment of mental illness