harebrain

dummy

bonehead chump dolt dunce fool idiot jackass knucklehead moron nincompoop ninny noodle numskull oaf simpleton tomfool

beefhead clodpoll halfwit hardhead

brain genius

blockhead blunderer bonehead botcher bumbler butcher butterfingers clod dolt donkey duffer dunce fool foul-up fumbler goofball idiot ignoramus incompetent klutz numskull spoiler

addlebrain clumsy oaf featherbrain goof-up mismanager muddler muffer screwup

brain genius

success

crackpot crank fanatic fiend freak loon looney lunatic maniac screwball zealot

sane person