THESAURUS
maniac
aliene, batty, bedlamite, berserk, borderline case, crackbrain, cracked, crackpot, crazed, crazy, delirious, dement, demented, demoniac, deranged, energumen, enthusiast, fan, fanatic, fiend, flake, fou, frantic, freak, frenetic, frenzied, furious, idiot, kook, loon, loony, lunatic, mad, madman, meshuggenah, non compos, noncompos, nut, phrenetic, psychopath, psychotic, rabid, raging, ranting, raving lunatic, screwball, unsound, violent, weirdo, wild, zealot
ROGET THESAURUS
maniac
Madman
N
madman, lunatic,
maniac, bedlamite, candidate for Bedlam, raver, madcap, crazy, energumen, automaniac, monomaniac, dipsomaniac, kleptomaniac, hypochondriac (low spirits), crank, Tom o'Bedlam, dreamer, rhapsodist, seer, highflier, enthusiast, fanatic, fanatico, exalte, knight errant, Don Quixote, idiot.