scenarist vs scenario

scenarist and scenario both are nouns.

Word	Noun	Adjective	Verb	Adverb
scenarist	Yes	No	No	No
scenario	Yes	No	No	No

scenarist (noun)	scenario (noun)
a writer of screenplays	an outline or synopsis of a play (or, by extension, of a literary work)
	a postulated sequence of possible events
	a setting for a work of art or literature