Synonyms and related words :
Boeotian, ass, block, clod, dimwit, dolt, donkey, dope, dullard, dumb cluck, dumbbell, dummy, dunce, gowk, idiot, imbecile, jackass, jerk, jobbernowl, lackwit, lamebrain, lightweight, looby, loon, niais, ninny, ninnyhammer, nitwit, noddy, put, stupid, thickwit, tomfool, witling