The Collaborative International Dictionary of English v.0.48:

Grizzled \Griz"zled\, a.
   Gray; grayish; sprinkled or mixed with gray; of a mixed white
   and black.
   [1913 Webster]

         Grizzled hair flowing in elf locks.      --Sir W.
                                                  Scott.
   [1913 Webster]

WordNet (r) 3.0 (2006):

grizzled
    adj 1: having dark hairs mixed with grey or white

Moby Thesaurus II by Grady Ward, 1.0:

81 Moby Thesaurus words for "grizzled":
   Quaker-colored, acier, argent, argentine, ashen, ashy, canescent,
   chalky, cinereous, cinerous, cretaceous, dapple, dapple-gray,
   dappled, dappled-gray, dingy, dismal, dove-colored, dove-gray,
   dreary, dull, dusty, fleecy-white, frosted, frosty, glaucescent,
   glaucous, gray, gray-black, gray-brown, gray-colored, gray-drab,
   gray-green, gray-spotted, gray-toned, gray-white, grayed, grayish,
   griseous, grizzle, grizzly, hoar, hoary, iron-gray, lactescent,
   lead-gray, leaden, lily-white, livid, marble, marmoreal, milky,
   mouse-colored, mouse-gray, mousy, niveous, pearl, pearl-gray,
   pearly, platinum, pure white, sad, silver, silver-gray, silvered,
   silvery, slate-colored, slaty, smoke-gray, smoky, snow-white,
   snowy, sober, somber, steel-gray, steely, stone-colored,
   swan-white, taupe, white, white as snow



Easton's 1897 Bible Dictionary:

Grizzled
   party-coloured, as goats (Gen. 31:10, 12), horses (Zech. 6:3,
   6).