insane

Synonyms balmy, barmy [chiefly British], bats, batty, bedlam, bonkers, brainsick, bughouse [slang], certifiable, crackbrained, cracked, crackers, crackpot, cranky [dialect], crazed, crazy, cuckoo, daffy, daft, demented, deranged, fruity [slang], gaga, haywire, kooky (also kookie), loco [slang], loony (also looney), loony tunes (or looney tunes), lunatic, mad, maniacal (also maniac), mental, meshuga (or meshugge also meshugah or meshuggah), moonstruck, non compos mentis, nuts, nutty, psycho, psychotic, scatty [chiefly British], screwy, unbalanced, unhinged, unsound, wacko (also whacko), wacky (also whacky), wud [chiefly Scottish]

Related Words dotty, fey, loopy, off, potty [chiefly British], teched (or tetched), touched; aberrant, delirious, delusional, delusionary, disordered, disturbed, neurotic, obsessive-compulsive, paranoiac (also paranoic), paranoid (also paranoidal), schizoid, schizophrenic, sociopathic; eccentric, odd, oddball, pixilated (also pixillated), queer, strange; foolish, senseless, witless; irrational, unreasonable; amok (or amuck), ape, ballistic, bananas, berserk, nuclear; depressed; distracted, distraught, frantic, frenzied, haywire, hysterical (also hysteric), raving, wigged-out; fixated, monomaniac, monomaniacal, obsessed

Phrases around the bend, off one's gourd, off one's head, off one's rocker, out of one's head (or mind), out to lunch [slang]

Near Antonyms clear, lucid, rational, reasonable; judicious, sensible, wise; healthy, normal, well-adjusted; unneurotic

Antonyms balanced, compos mentis, sane, sound, uncrazy

Synonyms absurd, bizarre, crazy, fanciful, foolish, insane, nonsensical, preposterous, unreal, wild

Related Words implausible, inconceivable, incredible, unbelievable, unimaginable, unthinkable; extravagant, grotesque; bizarro, curious, eccentric, far-out, funny, kinky, kooky (also kookie), odd, outlandish, out-of-the-way, outré, peculiar, quaint, queer, queerish, quirky, screwy, strange, wacky (also whacky), way-out, weird; farcical, laughable, ludicrous, ridiculous; Alice-in-Wonderland, Kafkaesque, nightmarish; dreamlike, surreal

Antonyms realistic, reasonable

Synonyms absurd, asinine, balmy, brainless, bubbleheaded, cockeyed, crackpot, crazy, cuckoo, daffy, daft, dippy, dotty, fatuous, featherheaded, fool, half-baked, harebrained, half-witted, inept, insane, jerky, kooky (also kookie), loony (also looney), lunatic, lunkheaded, mad, nonsensical, nutty, preposterous, sappy, screwball, senseless, silly, simpleminded, stupid, tomfool, unwise, wacky (also whacky), weak-minded, witless, zany

Related Words airheaded, birdbrained, boobish, brain-dead, chowderheaded, chuckleheaded, clueless, dense, dim, dim-witted, doltish, dopey (also dopy), dorky [slang], dull, dumb, dunderheaded, empty-headed, fatuous, feebleminded, gormless [chiefly British], idiotic (also idiotical), imbecile (or imbecilic), knuckleheaded, lamebrain (or lamebrained), mindless, moronic, oafish, obtuse, opaque, pinheaded, simple, slow, slow-witted, soft, softheaded, thoughtless, thick, thickheaded, unintelligent, vacuous, witless; fallacious, illogical, invalid, irrational, nonrational, surd, unreasonable, unreasoning, unsound, weak; farcical, laughable, ludicrous, ridiculous; notional; buffoonish, clownish; ill-advised, unconsidered, unreasoned

Near Antonyms brainy, bright, clever, intelligent, smart; logical, rational, reasonable, valid; well-advised

Antonyms judicious, prudent, sagacious, sage, sane, sapient, sensible, sound, wise

Synonyms baroque, devilish, exorbitant, extravagant, extreme, fancy, immoderate, inordinate, insane, intolerable, lavish, overdue, overextravagant, overmuch, overweening, plethoric, steep, stiff, towering, unconscionable, undue, unmerciful

Related Words boundless, endless, immeasurable, infinite, limitless; unbearable, unjustifiable, unwarranted; improper, inappropriate, thick, unseemly; unrestrained

Near Antonyms deficient, inadequate, insufficient; minimal, minimum

Antonyms middling, moderate, modest, reasonable, temperate