greenhorn(n = noun.person) cub, rookie - an awkward and inexperienced youth;
is a kind of beginner, initiate, novice, tiro, tyro
A raw, inexperienced person; one easily imposed upon. W. Irving. [1913 Webster]
greenhorn, n. an inexperienced or foolish person; a new recruit.
N ignoramus, dunce, wooden spoon, no scholar, (imbecility) 499 (folly) 501 moron, imbecile, idiot, fool, jerk, nincompoop, asshole, dilettante, sciolist, smatterer, dabbler, half scholar, charlatan, wiseacre, greenhorn, amateur, novice, tyro, numskull, lubber, fool, pedant, bookless, shallow, ignorant, a wit with dunces and a dunce with wits.
N fool, idiot, tomfool, wiseacre, simpleton, witling, dizzard, donkey, ass, ninny, ninnyhammer, chowderhead, chucklehead, dolt, booby, Tom Noddy, looby, hoddy-doddy, noddy, nonny, noodle, nizy, owl, goose, goosecap, imbecile, gaby, radoteur, nincompoop, badaud, zany, trifler, babbler, pretty fellow, natural, niais, child, baby, infant, innocent, milksop, sop, oaf, lout, loon, lown, dullard, doodle, calf, colt, buzzard, block, put, stick, stock, numps, tony, bull head, dunderhead, addlehead, blockhead, dullhead, loggerhead, jolthead, jolterhead, beetlehead, beetlebrain, grosshead, muttonhead, noodlehead, giddyhead, numbskull, thickskull, lackbrain, shallowbrain, dimwit, halfwit, lackwit, dunderpate, lunkhead sawney, gowk, clod, clod-hopper, clod-poll, clot-poll, clot-pate, bull calf, gawk, Gothamite, lummox, rube, men of Boeotia, wise men of Gotham, un sot a triple etage, sot, jobbernowl, changeling, mooncalf, gobemouche, dotard, driveler, old fogey, old woman, crock, crone, grandmother, cotquean, henhussy, incompetent (insanity), greenhorn, dunce, lubber, madman, one who will not set the Thames on fire, one who did not invent gunpowder, qui n'a pas invente' la poudre, no conjuror, fortuna favet fatuis, les fous font les festinas et les sages les mangen, nomina stultorum parietibus harrent, stultorum plena sunt omnia.
N dupe, gull, gudgeon, gobemouche, cull, cully, victim, pigeon, April fool, jay, sucker, laughingstock, Cyclops, simple Simon, flat, greenhorn, fool, puppet, cat's paw, credulous, mistaken.