Synonyms and related words :
Boeotian, absurd, addled, apish, asinine, backward, balmy, barmy, batty, beef-brained, beef-witted, beetleheaded, befooled, beguiled, besotted, blear-eyed, blear-witted, block, blockheaded, blockish, boneheaded, bootless, boring, bovine, brainless, brute, brutish, buffoonish, chuckleheaded, chumpish, clod, cloddish, cockamamie, cockeyed, cowish, crass, crazy, credulous, cretinous, cuckoo, daffy, daft, dazed, dense, dim, dim-witted, dimwit, dizzy, dolt, doltish, donkey, dope, dopey, doting, dozy, dull, dull-witted, dullard, dullhead, dumb, dumb cluck, dumbbell, dummkopf, dummy, dunce, duncical, duncish, empty-headed, fat, fatheaded, fatuitous, fatuous, flaky, fond, fool, foolhardy, foolheaded, foolish, frivolous, fuddled, futile, gaga, goofy, goosey, gowk, gross, gulled, half-assed, half-baked, half-witted, ho-hum, humdrum, idiot, idiotic, ignoramus, ill-advised, imbecile, imbecilic, inane, ineducable, inept, infatuated, insane, insipid, irrational, irresponsible, jerky, jobbernowl, klutzy, kooky, lackwit, lamebrain, laughable, lightweight, looby, loon, loony, ludicrous, lumbering, lumpish, mad, maudlin, mindless, monotonous, moron, moronic, niais, nincompoop, ninny, ninnyhammer, nitwit, noddy, nonsensical, numskulled, nutty, oafish, obtuse, opaque, pinhead, prosaic, put, retarded, ridiculous, risible, sappy, scatterbrained, screwy, senseless, sentimental, silly, simple, simpleton, slow, slow-witted, sluggish, sottish, stolid, subnormal, tedious, thick, thick-witted, thickheaded, thickwit, thoughtless, tiresome, torpid, unimaginative, uninspired, unintelligent, uninteresting, unteachable, vacuous, vapid, wacky, weak-minded, wet, witless, witling, wrongheaded