Without point or edge
Antonyms sharp*, sharpened, keen.
Lacking brightness or color
gloomy, sober, somber, drab, matte, dismal, bleak, dark, dingy, dim, dusky, dun, colorless, plain, obscure, cloudy, lackluster, tarnished, faded, unglazed, lusterless, opaque, leaden, grave, grimy, pitchy, sooty, inky, dead, black, coal-black, unlit, unlighted, sordid, dirty, muddy, murky, gray, ashen, wan, lifeless, rusty, flat, without snap*; see also dark 1.
Lacking intelligence or sensitivity; said usually of living beings
stupid, stolid, obtuse, sluggish, heavy, slow, retarded, witless, sleepy, backward, dense, dullwitted, tedious, boring, unintelligent, ignorant, unintellectual, vacuous, doltish, besotted, scatterbrained, feeble-minded, half-witted, addled, addlebrained, thick-witted, slow-witted, thick-skulled, imbecilic, insensate, dim, prosy, prosaic, unimaginative, fatuous, insensitive, unfeeling, unresponsive, numb, wooden, blunted, listless, apathetic, phlegmatic, not bright, torpid, spiritless, brainless, shallow, indolent, unentertaining, non compos mentis, simple-minded, simple, moronic, lumpish, stuffy, stodgy, dumb*, thick*, dopey*, lowbrow*, stupid as an ox*, blockheaded*, muscle-bound*, nitwitted*, dimwitted*, dead from the ears up*, not all there*; see also stupid 1.
Lacking interest; said usually of writing, speaking, or inanimate things
tedious, boring, tiresome, prosy, heavy, leaden, prosaic, trite, hackneyed, monotonous, humdrum, dreary, dismal, dry, arid, barren, colorless, insipid, vapid, flat, bland, uninteresting, deadly, longwinded, prolix, stupid, commonplace, ordinary, common, usual, unenlivened, stuffy, stodgy, old, ancient, stale, moth-eaten, out-of-date, antediluvian, archaic, hoary, worn-out, banal, tired, driveling, senseless, pointless, uninspiring, platitudinous, pedestrian, jejune, tame, routine, familiar, well-known, conventional, unimaginative, depressing, sluggish, plodding, repetitious, unvarying, boresome, abused, repetitive, oft-repeated, well-worn, fatiguing, wearisome, wearing, soporific, producing ennui, lifeless, wooden, characterless, wearying, tiring, unexciting, irksome, stereotyped, stereotypical, stock, the usual thing, the same old thing, slow, draggy, dry as dust, cut and dried, without any kick*, dead as a doornail*, blah*, ho-hum*.
Not loud or distinct
Showing little activity
slow, placid, languid, lethargic, still, sluggish, listless, lackadaisical, regular, depressed, inactive, lifeless, spiritless, uneventful, unexciting, slothful, without incident, quiet, even, torpid, inert, bovine, cowlike, routine, usual, accustomed, slack, monotonous, unresponsive, stagnant, dead, boring, falling off, apathetic, stolid, flat, lumpish, lumpy, bearish, poky, off*.
dull is specifically applied to a point or edge that has lost its previous sharpness a dull knife and generally connotes a lack of keenness, zest, spirit, intensity, etc. a dull book, a dull ache; blunt is often equivalent to dull, but specifically refers to a point or edge that is intentionally not sharp a blunt fencing saber; obtuse literally applies to a pointed end whose sides form an angle greater than 90â…“â…“â…“â…“â…“°, and figuratively connotes lack of understanding or sensitivity too obtuse to comprehend See also syn. study at stupid.
Having only a limited ability to learn and understand:backward, simple, simple-minded, slow, slow-witted. (Informal) soft. (Offensive) feeble-minded, half-witted, retarded, weak-minded. See ability
Lacking responsiveness or alertness:benumbed, insensible, insensitive, numb, stuporous, torpid, unresponsive, wooden. See awareness
Unwilling or unable to perceive:blind, purblind, uncomprehending, unperceptive. See see
Lacking passion and emotion:anesthetic, bloodless, insensate, insensible, insensitive. See attitude, feelings
In low spirits:blue, dejected, depressed, desolate, dispirited, down, downcast, downhearted, dysphoric, gloomy, heavy-hearted, low, melancholic, melancholy, sad, spiritless, tristful, unhappy, wistful. Idiom: down at (or in) the mouth. See happy
Characterized by reduced economic activity:down, off, slack, slow, sluggish, soft. See increase
Not physically sharp or keen:blunt. See sharp
Arousing no interest or curiosity:boring, drear, dreary, dry, humdrum, irksome, monotonous, stuffy, tedious, tiresome, uninteresting, weariful, wearisome, weary. See excite
Lacking liveliness, charm, or surprise:arid, aseptic, colorless, drab, dry, earthbound, flat, flavorless, lackluster, lifeless, lusterless, matter-of-fact, pedestrian, prosaic, spiritless, sterile, stodgy, unimaginative, uninspired. See excite
Lacking vividness in color:dim, drab, flat, muddy, murky. See colors
Lacking gloss and luster:dim, flat, lackluster, lusterless, mat. See light
To make or become less keen or responsive:dim, hebetate, stupefy. See awareness
To render less sensitive:benumb, blunt, deaden, desensitize, numb. Idiom: take the edge off. See awareness
To make or become less sharp-edged:blunt, turn. Idiom: take the edge off. See sharp
To make dim or indistinct:becloud, bedim, befog, blear, blur, cloud, dim, eclipse, fog, gloom, mist, obfuscate, obscure, overcast, overshadow, shadow. See clear