nut

1 a person of odd or whimsical habits <a show devoted to those lovable nuts who collect the weirdest things just for fun> Synonyms character, codger, crack, crackbrain, crackpot, crank, flake, fruitcake, head case, kook, eccentric, nutcase, nutter [British slang], oddball, oddity, original, quiz, screwball, weirdo, zanyRelated Words bohemian, maverick, nonconformist, quixote; coot, geezer; curio, rarity; freak; fantast, fantasticoNear Antonyms conformer, conformist, follower, sheep

2 a person who lacks good sense or judgment <anyone who runs into traffic like that sure is a nut> Synonyms berk [British], booby, charlie (also charley) [British], cuckoo, ding-a-ling, dingbat, ding-dong, dipstick, doofus [slang], featherhead, git [British], goose, half-wit, jackass, lunatic, mooncalf, nincompoop, ninny, ninnyhammer, nit [chiefly British], nitwit, fool, nutcase, simp, simpleton, turkey, yo-yoRelated Words daredevil; madman, madwoman; airhead, birdbrain, blockhead, cretin, dodo, dolt, donkey, dope, dork [slang], dumbbell, dummy, dunce, fathead, gander, goon, half-wit, idiot, ignoramus, imbecile, know-nothing, knucklehead, moron, numskull (or numbskull), pinhead, schlub (also shlub) [slang], schlump [slang], schnook [slang], stock; featherbrain, scatterbrain; butt, dupe, laughingstock, mockery, monkey; chump, loser, schlemiel (also shlemiel); character, codger, crackbrain, crackpot, crank, kook, oddball, screwball, weirdoNear Antonyms sage, thinker; brain, genius

3 a person with a strong and habitual liking for something <a baseball nut who waited 86 years for the Boston Red Sox to win the World Series> Synonyms addict, aficionado (also afficionado), buff, bug, devotee, enthusiast, fanatic, fancier, fiend, fool, freak, habitué (also habitue), head, hound, junkie (also junky), lover, maniac, maven (also mavin), fan, suckerRelated Words groupie; admirer, amateur, collector, connoisseur, dilettante; authority, expert; adherent, convert, cultist, disciple, follower, hanger-on, votary; advocate, apostle, backer, champion, evangelist, exponent, friend, patron, promoter, proponent, supporter; partisan (also partizan), zealot; booster, rooter, well-wisher; faddistNear Antonyms nonadmirer; belittler, carper, critic, detractorAntonyms nonfan

4 a person judged to be legally or medically insane <the man walking down the street talking to himself looked like a nut until we realized he was talking into his cell phone> Synonyms bug, crackbrain, crazy, fool, fruitcake, head case, loon, loony, maniac, lunatic, nutcase, nutter [British slang], psycho, psychopath, sickie, sicko, wacko (also whacko)Related Words madman, madwoman; abnormal, deviant; manic-depressive, monomaniac, mythomaniac, neurotic, obsessive, obsessive-compulsive, paranoid, psychoneurotic, psychotic, schizo, schizoid, schizophrene, schizophrenic, sociopath; character, codger, crack, crackpot, crank, eccentric, fantastic (also fantastical), flake, kook, oddball, oddity, original, quiz, screwball, tyke (also tike) [chiefly British], weirdo, zany; case, patient

5 something that requires thought and skill for resolution <the question of how to increase functionality without decreasing efficiency may prove to be a tough nut to crack> Synonyms case, challenge, knot, matter, problem, troubleRelated Words issue, question; corner, fix, hole, hot water, jam, mire, pickle, predicament, quagmire, spot; crux, Gordian knot, sticky wicket, toughie (also toughy); catch-22, dilemma, quandary; catch, glitch, hitch, pitfall, snag; conundrum, enigma, mystery, puzzle, puzzlement, riddle; brainteaser, perplexer, poser, stumperNear Antonyms magic bullet, silver bullet; cure-all, panaceaAntonyms answer, solution

6 slang  the upper or front part of the body that contains the brain, the major sense organs, and the mouth <he didn't appreciate his friend's jibe about watching his big nut when getting into the car> Synonyms bean, block [slang], dome, mazard (or mazzard) [chiefly dialect], nob, noddle, noggin, noodle, head [slang], pate, pollRelated Words cranium, crown, scalp, skull; occiput

7 nuts pl  language, behavior, or ideas that are absurd and contrary to good sense <responding to your opponent's every argument with “Nuts!” is not exactly finely reasoned refutation> Synonyms applesauce [slang], balderdash, baloney (also boloney), beans, bilge, blah (also blah-blah), blarney, blather, blatherskite, blither, bosh, bull [slang], bunk, bunkum (or buncombe), claptrap, codswallop [British], crapola [slang], crock, drivel, drool, fiddle, fiddle-faddle, fiddlesticks, flannel [British], flapdoodle, folderol (also falderal), folly, foolishness, fudge, garbage, guff, hogwash, hokeypokey, hokum, hoodoo, hooey, horsefeathers [slang], humbug, humbuggery, jazz, malarkey (also malarky), moonshine, muck, nerts [slang], nuts, piffle, poppycock, punk, rot, rubbish, senselessness, silliness, slush, stupidity, taradiddle (or tarradiddle), tommyrot, tosh, trash, trumpery, twaddleRelated Words absurdity, asininity, fatuity, foolery, idiocy, imbecility, inaneness, inanity, insanity, kookiness, lunacy; absurdness, craziness, madness, senselessness, witlessness; hoity-toity, monkey business, monkeyshine(s), shenanigan(s), tomfoolery; gas, hot air, rigmarole (also rigamarole); double-talk, greek, hocus-pocusNear Antonyms levelheadedness, rationality, reasonability, reasonableness, sensibleness; common sense, horse sense, sense; discernment, judgment (or judgement), wisdom