Synonyms and related words :
Boeotian, aliene, bedlamite, block, borderline case, clod, crackbrain, crackpot, dement, demoniac, dimwit, dolt, donkey, dope, dullard, dumb cluck, dumbbell, dummy, dunce, energumen, fanatic, flake, fou, gowk, idiot, jobbernowl, kook, lackwit, lamebrain, lightweight, looby, loony, lunatic, madman, maniac, meshuggenah, niais, nincompoop, ninny, ninnyhammer, nitwit, noddy, non compos, noncompos, nut, phrenetic, put, raving lunatic, screwball, stupid, thickwit, weirdo, witling