imperialist vs imperialism

imperialist and imperialism both are nouns.

Word	Noun	Adjective	Verb	Adverb
imperialist	Yes	Yes	No	No
imperialism	Yes	No	No	No

imperialist (noun)	imperialism (noun)
a believer in imperialism	any instance of aggressive extension of authority
	a political orientation that advocates imperial interests
	a policy of extending your rule over foreign countries

imperialist (adjective)	imperialism (adjective)
of or relating to imperialism