A person lacking intelligence or common sense.

synonym: simple.

Roget 501: 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 [U.S.], gowk^†; clod, clod-hopper; clod-poll, clot-poll, clot-pate; bull calf; gawk, Gothamite, lummox, rube [U.S.]; men of Boeotia, wise men of Gotham.    un sot a triple etage [Fr.], sot; jobbernowl^†, changeling, mooncalf, gobemouche^†.    dotard, driveler; old fogey, old woman, crock; crone, grandmother; cotquean^†, henhussy^†.    incompetent (insanity) 503.    greenhorn etc. (dupe) 547; dunce etc. (ignoramus) 493; lubber etc. (bungler) 701; madman etc. 504.    one who will not set the Thames on fire; one who did not invent gunpowder, qui n'a pas invente' la poudre [Fr.]; no conjuror.    ... show more

Dutch: sul, simpele, lobbes
Polish: prostaczek