nutcase

1 a person judged to be legally or medically insane some nutcase was arrested for sending the threatening letters to the White House Synonyms bug, crackbrain, crazy, fool, fruitcake, head case, loon, loony, maniac, nut, lunatic, 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

2 a person of odd or whimsical habits around the condo complex she's known as the nutcase who consistently ignores the rules Synonyms character, codger, crack, crackbrain, crackpot, crank, flake, fruitcake, head case, kook, nut, eccentric, 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

3 a person who lacks good sense or judgment only a nutcase would try to accelerate a campfire by dousing it with gasoline 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, nut, fool, 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