airhead, birdbrain, blockhead, bonehead, bubblehead, chowderhead, chucklehead, clodpoll(or clodpole), clot(British), cluck, clunk, cretin, cuddy(or cuddie, British dialect), deadhead, dim bulb(slang), dimwit, dip, dodo, dolt, donkey, doofus(slang), dope, dork(slang), dullard, dum-dum, dumbbell, dumbhead, dummkopf, dummy, dunce, dunderhead, fathead, gander, golem, goof, goon, half-wit, hammerhead, hardhead, idiot, ignoramus, imbecile, jackass, know-nothing, knucklehead, lamebrain, loon, lump, lunkhead, meathead, mome(archaic), moron, mug(chiefly British), mutt, natural, nimrod(slang), nincompoop, ninny, ninnyhammer, nit(chiefly British), nitwit, noddy, noodle, numskull(or numbskull), oaf, pinhead, prat(British), ratbag(chiefly Australian), saphead, schlub(also shlub, slang), schnook(slang), simpleton, stock, stupe, stupid, thickhead, turkey, woodenhead, yahoo, yo-yo

booby, buffoon, fool, goose, loony, lunatic, madman, nut, zanylosergawkfeatherbrain, scatterbrainbeast, boor, cad, churl, clown, creep, cur, heel, jerk, skunk, snake, stinker, villain

dumb cluck