Ignoramus

Moby Thesaurus II by Grady Ward, 1.0:

abecedarian, alphabetarian, apprentice, articled clerk, ass,
beginner, boot, born fool, buffoon, catechumen, clown, dabbler,
debutant, dilettante, doodle, dullard, dullhead, dumbbell,
dummkopf, dummy, dunce, egregious ass, entrant, figure of fun,
fledgling, fool, freshman, greenhorn, greeny, idiot, illiterate,
illiterati, inductee, initiate, jackass, know-nothing, lowbrow,
lunatic, middlebrow, milksop, mooncalf, moron, neophyte, new boy,
newcomer, no scholar, novice, novitiate, perfect fool, postulant,
probationer, probationist, puddinghead, raw recruit, recruit,
rookie, schmuck, simpleton, softhead, sop, stupid, stupid ass,
tenderfoot, tomfool, tyro, unintelligentsia, zany