Synonyms and related words :
ament, born fool, bungler, clot, congenital idiot, cretin, defective, dullard, dullhead, dumbbell, dummkopf, dummy, golem, half-wit, idiot, ignoramus, imbecile, juggins, mongoloid idiot, moron, natural, natural idiot, natural-born fool, simp, stupid, zany