Silly

birdbrained, ditzy ( ditsy), dizzy, featherbrained, flighty, frivolous, frothy, futile, goofy, harebrained, light-headed, light-minded, puerile, scatterbrained, silly, yeasty

fatuous, foolish, inane, nonsensical, thoughtless, witless; crazy, daffy, daft, fruity; exuberant, flippant, fluttery, giggly, happy, light, lighthearted, playful; sappy, shallow, superficial

grave, melancholy, somber ( sombre), thoughtful; dignified, heavy, no-nonsense, sedate, severe, solemn, staid

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 ( kookie), loony ( looney), lunatic, lunkheaded, mad, nonsensical, nutty, preposterous, sappy, screwball, senseless, silly, simpleminded, stupid, tomfool, unwise, wacky ( whacky), weak-minded, witless, zany

airheaded, birdbrained, boobish, brain-dead, chowderheaded, chuckleheaded, clueless, dense, dim, dim-witted, doltish, dopey ( dopy), dorky [], dull, dumb, dunderheaded, empty-headed, fatuous, feebleminded, gormless [], idiotic ( idiotical), imbecile ( imbecilic), knuckleheaded, lamebrain ( 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

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

absurd, cockamamy ( cockamamie), comical, derisive, derisory, farcical, laughable, ludicrous, pathetic, preposterous, risible, silly

asinine, brainless, dumb, fatuous, foolish, half-baked, half-witted, harebrained, idiotic ( idiotical), imbecile ( imbecilic), inane, jerky, moronic, nonsensical, simpleminded, stupid, unwise, weak-minded, witless; balmy, cockeyed, crazy, cuckoo, daffy, daft, dotty, insane, kooky ( kookie), loony ( looney), lunatic, mad, nutty, screwball, senseless, wacky ( whacky); fantastic ( fantastical), far-fetched, inconceivable, incredible, unbelievable, unreal, unrealistic, unreasonable; illogical, irrational

earnest, serious, solemn; believable, conceivable, credible, logical, rational, realistic, reasonable, sensible

addle, addled, addlepated, bedeviled, befogged, befuddled, bemused, bewildered, bushed, confounded, confused, dazed, distracted, dopey ( dopy), fogged, mixed-up, muddleheaded, muzzy, pixilated ( pixillated), punch-drunk, punchy, raddled, shell-shocked, silly, slaphappy, spaced-out ( spaced), spacey ( spacy), stunned, stupefied, zonked, zonked-out

senseless, unconscious

alert, conscious