The Collaborative International Dictionary of English v.0.48:

Glaucous \Glau"cous\ (gl[add]"k[u^]s), a. [L. glaucus, Gr.
   glayko`s.]
   1. Of a sea-green color; of a dull green passing into grayish
      blue. --Lindley.
      [1913 Webster]

   2. (Bot.) Covered with a fine bloom or fine white powder
      easily rubbed off, as that on a blue plum, or on a cabbage
      leaf. --Gray.
      [1913 Webster]

WordNet (r) 3.0 (2006):

glaucous
    adj 1: having a frosted look from a powdery coating, as on
           plants; "glaucous stems"; "glaucous plums"; "glaucous
           grapes"

Moby Thesaurus II by Grady Ward, 1.0:

118 Moby Thesaurus words for "glaucous":
   Quaker-colored, acier, aestival, alabaster, alabastrine, albescent,
   ashen, ashy, beryl-green, berylline, blue-green, bluish-green,
   canescent, chartreuse, chloranemic, chlorine, chlorotic, cinereous,
   cinerous, citrine, citrinous, cream, creamy, dapple, dapple-gray,
   dappled, dappled-gray, dingy, dismal, dove-colored, dove-gray,
   dreary, dull, dun-white, dusty, eggshell, emerald, fair, foliaged,
   glaucescent, glaucous-green, grassy, gray, gray-black, gray-brown,
   gray-colored, gray-drab, gray-green, gray-spotted, gray-toned,
   gray-white, grayed, grayish, green, green as grass, green-blue,
   greenish, greenish-blue, greenish-yellow, greensick, griseous,
   grizzle, grizzled, grizzly, holly, iron-gray, ivory, ivory-white,
   ivy, ivy-green, lead-gray, leaden, leafy, leaved, light,
   lint-white, livid, mouse-colored, mouse-gray, mousy, off-white,
   olivaceous, olive, olive-green, pale, pearl, pearl-gray, pearly,
   pearly-white, porraceous, sad, silver, silver-gray, silvered,
   silvery, slate-colored, slaty, smaragdine, smoke-gray, smoky,
   sober, somber, springlike, steel-gray, steely, stone-colored,
   summerlike, summery, taupe, verdant, verdurous, vernal, vernant,
   vert, virescent, whitish, whity, yellowish-green