brainless

1 not having or showing an ability to absorb ideas readily a teacher who affirms that there are no brainless students, only lazy ones Synonyms airheaded, birdbrained, bonehead, boneheaded, brain-dead, stupid, bubbleheaded, chuckleheaded, dense, dim, dim-witted, doltish, dopey (also dopy), dorky [slang], dull, dumb, dunderheaded, empty-headed, fatuous, gormless [chiefly British], half-witted, knuckleheaded, lamebrain (or lamebrained), lunkheaded, mindless, oafish, obtuse, opaque, pinheaded, senseless, simple, slow, slow-witted, soft, softheaded, thick, thickheaded, thick-witted, unintelligent, unsmart, vacuous, weak-minded, witlessRelated Words cretinous, feebleminded, simpleminded; boobish, foolish, idiotic (also idiotical), imbecile (or imbecilic), moronic; ignorant, illiterate, lowbrow, uneducated, uninformed, unintellectual, untaught, unthinking; absurd, asinine, balmy, cockeyed, crackpot, crazy, cuckoo, daffy, daft, dippy, dotty, featherheaded, fool, half-baked, harebrained, insane, kooky (also kookie), loony (also looney), lunatic, mad, nonsensical, nutty, preposterous, sappy, screwball, silly, tomfool, unwise, wacky (also whacky), zany; fallacious, illogical, invalid, irrational, unreasonableNear Antonyms ingenious, resourceful; acute, astute, discerning, insightful, keen, knowing, perceptive, percipient, perspicacious, sagacious, sage, sapient, savvy, wise; cerebral, erudite, highbrow, intellectual, knowledgeable, learned, literate, scholarly, thinking, well-read; educated, informed, schooled, skilled, trained; crafty, cunning, foxy, shrewd, wily; judicious, prudent, sane, sensible, sound; logical, rational, reasonable, validAntonyms apt, brainy, bright, brilliant, clever, fast, hyperintelligent, intelligent, keen, nimble, quick, quick-witted, sharp, sharp-witted, smart, supersmart, ultrasmart

2 showing or marked by a lack of good sense or judgment a brainless decision to talk on her cell phone while weaving in and out of traffic Synonyms absurd, asinine, balmy, foolish, 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, 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