dumb

1 deliberately refraining from speech the mayor has chosen to remain dumb about her activities that night Synonyms silent, mum, mute, muted, speechless, uncommunicative, wordlessRelated Words inarticulate, tongue-tied; nonvocal, voiceless; dumbstruck; sulking, sulky, sullenNear Antonyms articulate, eloquent, fluent, voluble, well-spoken; gabby, garrulous, loquacious, talkative, talky; outspoken, unreserved, vocal; facile, glib, silver-tongued, smooth-tonguedAntonyms communicative, speaking, talking

2 not having or showing an ability to absorb ideas readily don't call him dumb just because he makes the occasional mistake like the rest of us Synonyms airheaded, birdbrained, bonehead, boneheaded, brain-dead, brainless, bubbleheaded, chuckleheaded, dense, dim, dim-witted, doltish, dopey (also dopy), dorky [slang], dull, stupid, 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

3 tending not to speak frequently (as by habit or inclination) he prefers to remain dumb, and replies in monosyllables if really pressed Synonyms closemouthed, silent, laconic, reserved, reticent, taciturn, tight-lipped, uncommunicativeRelated Words aloof, indrawn, inhibited, introverted, reserved, restrained; sedate, self-contained, sober, staid; backward, bashful, coy, demure, diffident, modest, retiring, self-effacing, sheepishNear Antonyms free-spoken, outspoken, vocal; gossipy, talebearing; diffuse, long-winded, prolix, rambling, verbose, windy, wordy; extroverted (also extraverted), gregarious, outgoing, sociableAntonyms blabby, chatty, communicative, conversational, gabby, garrulous, loquacious, motormouthed, mouthy, talkative, talky, unreserved