Synonyms of imbecile

1 Syllable
schnook, ass, clod, oaf, slow, dull, boob, thick, schmuck, fool, fools, schmoes, schmo
2 Syllables
dullard, birdbrains, numbskull, birdbrain, ravers, oxen, airhead, idiot, jughead, dummkopf, dimwit, turkey, morons, numskull, witless, thickhead, dunce, lame-brain, lagging, ding-dong, half-wit, moron, ninnies, cretin, fathead, simple, halfwit, bruiser, gorked, ninny, bruisers, softhead, lummox, lunkhead, mooncalf, jerked, fatuous, backward, cretins, dumdum, brainless, jerking, witling, nitwit
3 Syllables
simpleton, nincompoop, muttonhead, inane, dim-witted, half-witted, squirrelly, senile, retardo, dunderhead, madperson, idiotic, senescent, deranged, bonehead, ludicrous, retarded, moronic
4 Syllables
ignoramus, feeble-minded, simple-minded, asinine, addlepate, imbecilic
5 Syllables
unprogressive, anencephalic, anencephalous, underachieving