The Collaborative International Dictionary of English v.0.48:

Dreary \Drear"y\ (dr[=e]r"[y^]), a. [Compar. Drearier; superl.
   Dreariest.] [OE. dreori, dreri, AS. dre['o]rig, sad; akin
   to G. traurig, and prob. to AS. dre['o]san to fall, Goth.
   driusan. Cf. Dross, Drear, Drizzle, Drowse.]
   1. Sorrowful; distressful. [Obs.] " Dreary shrieks."
      --Spenser.
      [1913 Webster]

   2. Exciting cheerless sensations, feelings, or associations;
      comfortless; dismal; gloomy. " Dreary shades." --Dryden.
      "The dreary ground." --Prior.
      [1913 Webster]

            Full many a dreary anxious hour.      --Keble.
      [1913 Webster]

            Johnson entered on his vocation in the most dreary
            part of that dreary interval which separated two
            ages of prosperity.                   --Macaulay.
      [1913 Webster]

WordNet (r) 3.0 (2006):

dreary
    adj 1: lacking in liveliness or charm or surprise; "her drab
           personality"; "life was drab compared with the more
           exciting life style overseas"; "a series of dreary dinner
           parties" [syn: drab, dreary]
    2: causing dejection; "a blue day"; "the dark days of the war";
       "a week of rainy depressing weather"; "a disconsolate winter
       landscape"; "the first dismal dispiriting days of November";
       "a dark gloomy day"; "grim rainy weather" [syn: blue,
       dark, dingy, disconsolate, dismal, gloomy, grim,
       sorry, drab, drear, dreary]

Moby Thesaurus II by Grady Ward, 1.0:

228 Moby Thesaurus words for "dreary":
   Quaker-colored, acier, affecting, afflictive, apocalyptic, arid,
   ashen, ashy, bad, baleful, banausic, baneful, barren, bitter,
   black, blah, blank, bleak, bloodless, blue, bodeful, boding,
   boring, broken-record, canescent, characterless, cheerless,
   cinereous, cinerous, cold, colorless, comfortless, dapple,
   dapple-gray, dappled, dappled-gray, dark, dead, deplorable,
   depressed, depressing, depressive, dim, dingy, dire, discomforting,
   dismal, dismaying, dispiriting, distressful, distressing, doleful,
   dolorific, dolorogenic, dolorous, doomful, dove-colored, dove-gray,
   downcast, drab, draggy, drear, drearisome, dry, dryasdust, dull,
   dusty, effete, elephantine, empty, etiolated, everlasting, evil,
   evil-starred, fade, fateful, flat, foreboding, forlorn, funebrial,
   funereal, glaucescent, glaucous, gloomy, glum, grave, gray,
   gray-black, gray-brown, gray-colored, gray-drab, gray-green,
   gray-spotted, gray-toned, gray-white, grayed, grayish, grievous,
   grim, griseous, grizzle, grizzled, grizzly, harping, heavy, ho-hum,
   hollow, humdrum, ill, ill-boding, ill-fated, ill-omened,
   ill-starred, inane, inauspicious, inexcitable, insipid, invariable,
   iron-gray, jejune, jog-trot, joyless, lamentable, lead-gray,
   leaden, lifeless, livid, long-winded, low-spirited, lowering,
   melancholy, menacing, miserable, monotone, monotonous, morose,
   mournful, mouse-colored, mouse-gray, mousy, moving,
   of evil portent, ominous, oppressive, ordinary, painful, pale,
   pallid, pathetic, pearl, pearl-gray, pearly, pedestrian, piteous,
   pitiable, plodding, poignant, pointless, poky, ponderous,
   portending, portentous, prolix, prosaic, regrettable, rueful,
   run-of-the-mill, sad, saddening, saturnine, sharp, silver,
   silver-gray, silvered, silvery, singsong, sinister, slate-colored,
   slaty, slow, smoke-gray, smoky, sober, solemn, somber, sombrous,
   sore, sorrowful, spiritless, steel-gray, steely, sterile, stiff,
   stodgy, stone-colored, stuffy, superficial, tasteless, taupe,
   tedious, threatening, tiresome, tiring, touching, treadmill,
   triste, uncomfortable, uneventful, unexciting, unfavorable,
   unfortunate, unhappy, uninteresting, unlively, unlucky,
   unpromising, unpropitious, untoward, unvarying, vapid, weariful,
   wearisome, weary, wearying, woebegone, woeful, wooden, wretched