optimist vs millenarist

optimist and millenarist both are nouns.

Word	Noun	Adjective	Verb	Adverb
optimist	Yes	No	No	No
millenarist	Yes	No	No	No

As nouns, millenarist is a hyponym of optimist; that is, millenarist is a word with a more specific, narrower meaning than optimist:

optimist: a person disposed to take a favorable view of things
millenarist: a person who believes in the coming of the millennium (a time of great peace and prosperity)

Other hyponyms of optimist include chiliast, millenarian.

optimist (noun)	millenarist (noun)
a person disposed to take a favorable view of things	a person who believes in the coming of the millennium (a time of great peace and prosperity)