anaudic, aphasic, aphonic, at a loss for words, breathless, brief, close, close-tongued, closemouthed, concise, curt, economical of words, inarticulate, incapable of speech, incoherent, indisposed to talk, laconic, mousy, mum, mute, noiseless, non-vocal, pantomimic, quiet, refusing to speak, reserved, reticent, silent, soundless, speechless, taciturn, terse, tight-lipped, tongue-tied, tongueless, uncommunicative, unconversant, unloquacious, untalkative, voiceless, word-bound, wordless

Boeotian, addlepated, animal, animalian, animalic, animalistic, apish, asinine, awkward, batty, beastlike, beastly, beef-brained, beef-witted, befooled, beguiled, besotted, bestial, bird-brained, blankminded, blockheaded, blockish, bovine, brainless, brusque, brutal, brute, brutelike, brutish, buffoonish, callow, chumpish, cloddish, cockeyed, cowish, crass, crazy, credulous, daffy, daft, dazed, dense, dim-witted, dizzy, doltish, dopey, doting, dozy, dull, dullard, dumbfounded, dumbstricken, dumbstruck, duncical, duncish, empty, empty-headed, exanimate, fat, fatheaded, fatuitous, fatuous, featherbrained, feebleminded, flaky, fond, fool, foolheaded, foolish, fuddled, futile, gaga, gauche, gaumless, goofy, gormless, green, groping, gross, gulled, half-baked, idiotic, ignorant, imbecile, imbecilic, inane, inanimate, inanimated, indistinct, ineducable, inept, inert, inexperienced, infatuated, innocent, insane, insensate, insensible, insentient, instinctive, instinctual, klutzy, know-nothing, kooky, lifeless, loony, loutish, lumpish, mad, maudlin, maundering, mentally deficient, mindless, moronic, naive, nescient, nonconscious, nonrational, numskulled, nutty, oafish, obtuse, opaque, pea-brained, purblind, raw, sappy, screwy, senseless, sentimental, short, silent, silly, simple, simple-minded, slow, slow-witted, snug, sottish, soulless, sparing of words, speechless, stricken dumb, stunned, stupid, subhuman, thick, thick-witted, thickheaded, thoughtless, unacquainted, unanimated, unapprized, uncomprehending, unconscious, unenlightened, unfamiliar, unfeeling, unilluminated, uninformed, uninitiated, unintelligent, unknowing, unripe, unteachable, unversed, vacuous, vapid, wacky, wet, witless, wrongheaded