harebrained

1 lacking in seriousness or maturity <the movie follows the harebrained antics of a pair of stoners who seem incapable of growing up> Synonyms birdbrained, ditzy (or ditsy), dizzy, featherbrained, flighty, frivolous, frothy, futile, goofy, giddy, light-headed, light-minded, puerile, scatterbrained, silly, yeastyRelated Words fatuous, foolish, inane, nonsensical, thoughtless, witless; crazy, daffy, daft, fruity; exuberant, flippant, fluttery, giggly, happy, light, lighthearted, playful; sappy, shallow, superficialNear Antonyms grave, melancholy, somber (or sombre), thoughtful; dignified, heavy, no-nonsense, sedate, severe, solemn, staidAntonyms earnest, serious, serious-minded, sober, unfrivolous

2 showing or marked by a lack of good sense or judgment <a harebrained idea to go for a hike in an area where grizzly bear attacks had recently been reported> Synonyms absurd, asinine, balmy, brainless, bubbleheaded, cockeyed, crackpot, crazy, cuckoo, daffy, daft, dippy, dotty, fatuous, featherheaded, fool, half-baked, foolish, 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, zanyRelated 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, unreasonedNear Antonyms brainy, bright, clever, intelligent, smart; logical, rational, reasonable, valid; well-advisedAntonyms judicious, prudent, sagacious, sage, sane, sapient, sensible, sound, wise