fantast

noun

1. (archaic)One whose manners or ideas are fantastic and fanciful; a dreamer.

   “He is indeed all this; and what he has more than all this peculiar to himself, I seem to convey to my own mind in some measure by saying, — that he is a quiet and sublime enthusiast with a strong tinge of the fantast, — the humourist constantly mingling with, and flashing across, the philosopher, as the darting colours in shot silk play upon the main dye.”

   “I recall one particularly heady Outreach meeting, in 1985, at which one of the speakers was a fantast named Jack Wheeler, who liked to say that Izvestia had described him as an “ideological gangster” […].”