The Collaborative International Dictionary of English v.0.48:

Drab \Drab\, a.
   Of a color between gray and brown. -- n. A drab color.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Drab \Drab\ (dr[a^]b), n. [AS. drabbe dregs, lees; akin to D.
   drab, drabbe, dregs, G. treber; for sense 1, cf. also Gael.
   drabag a slattern, drabach slovenly. Cf. Draff.]
   1. A low, sluttish woman. --King.
      [1913 Webster]

   2. A lewd wench; a strumpet. --Shak.
      [1913 Webster]

   3. A wooden box, used in salt works for holding the salt when
      taken out of the boiling pans.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Drab \Drab\, v. i. [imp. & p. p. Drabbed; p. pr. & vb. n.
   Drabbing.]
   To associate with strumpets; to wench. --Beau. & Fl.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Drab \Drab\, n. [F. drap cloth: LL. drappus, trapus, perh.
   orig., a firm, solid stuff, cf. F. draper to drape, also to
   full cloth; prob. of German origin; cf. Icel. drepa to beat,
   strike, AS. drepan, G. treffen; perh. akin to E. drub. Cf.
   Drape, Trappings.]
   1. A kind of thick woolen cloth of a dun, or dull brownish
      yellow, or dull gray, color; -- called also drabcloth.
      [1913 Webster]

   2. A dull brownish yellow or dull gray color.
      [1913 Webster]

WordNet (r) 3.0 (2006):

drab
    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: lacking brightness or color; dull; "drab faded curtains";
       "sober Puritan grey"; "children in somber brown clothes"
       [syn: drab, sober, somber, sombre]
    3: of a light brownish green color [syn: olive-drab, drab]
    4: 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]
    n 1: a dull greyish to yellowish or light olive brown [syn:
         olive drab, drab]

Moby Thesaurus II by Grady Ward, 1.0:

94 Moby Thesaurus words for "drab":
   bag, bat, bawd, beige, beldam, biddy, bleak, boring, brown,
   brownish, brownish-yellow, brunet, cheerless, chocolate, cinnamon,
   cocoa, cocoa-brown, coffee, coffee-brown, colorless, crone,
   cruiser, dead, deadened, desolate, dingy, dismal, dispiriting,
   dowdy, dreary, dull, dun, dun-brown, dun-drab, ecru, faded, fawn,
   fawn-colored, fille de joie, flat, fuscous, gray, grege, grey, hag,
   harlot, hazel, hooker, humdrum, hustler, khaki, lackluster,
   lifeless, lurid, lusterless, mat, monotonous, muddy, murky,
   nightwalker, nut-brown, olive-brown, olive-drab, prosaic, prosy,
   repetitive, same, samely, seal, seal-brown, sepia, slut,
   snuff-colored, somber, sorrel, streetwalker, subfusc, tan, taupe,
   tawny, tedious, toast, toast-brown, traipse, trot, umber,
   umber-colored, unrelieved, walnut, walnut-brown, wan, whore, witch,
   yellowish-brown