The Collaborative International Dictionary of English v.0.48:

Snowy \Snow"y\, a.
   1. White like snow. "So shows a snowy dove trooping with
      crows." --Shak.
      [1913 Webster]

   2. Abounding with snow; covered with snow. "The snowy top of
      cold Olympus." --Milton.
      [1913 Webster]

   3. Fig.: Pure; unblemished; unstained; spotless.
      [1913 Webster]

            There did he lose his snowy innocence. --J. Hall
                                                  (1646).
      [1913 Webster]

   Snowy heron (Zool.), a white heron, or egret (Ardea
      candidissima), found in the Southern United States, and
      southward to Chile; -- called also plume bird.

   Snowy lemming (Zool.), the collared lemming (Cuniculus
      torquatus), which turns white in winter.

   Snowy owl (Zool.), a large arctic owl (Nyctea Scandiaca,
      or Nyctea nivea) common all over the northern parts of
      the United States and Europe in winter time. Its plumage
      is sometimes nearly pure white, but it is usually more or
      less marked with blackish spots. Called also white owl.


   Snowy plover (Zool.), a small plover (Aegialitis nivosa)
      of the western parts of the United States and Mexico. It
      is light gray above, with the under parts and portions of
      the head white.
      [1913 Webster]

WordNet (r) 3.0 (2006):

snowy
    adj 1: marked by the presence of snow; "a white Christmas"; "the
           white hills of a northern winter" [syn: white, snowy]
    2: covered with snow; "snow-clad hills"; "snow-covered roads";
       "a long snowy winter" [syn: snow-clad, snow-covered,
       snowy]
    3: of the white color of snow [syn: snow-white, snowy]

Moby Thesaurus II by Grady Ward, 1.0:

71 Moby Thesaurus words for "snowy":
   argent, argentine, blotless, canescent, chalky, chaste, clean,
   cleanly, cretaceous, fleecy-white, frosted, frosty, grizzled,
   grizzly, hoar, hoary, immaculate, innocent, lactescent, lily-white,
   marble, marmoreal, milky, nival, niveous, platinum, pure,
   pure in heart, pure white, purehearted, sexually innocent, silver,
   silvered, silvery, snow-bearded, snow-blanketed, snow-capped,
   snow-clad, snow-crested, snow-drifted, snow-driven, snow-encircled,
   snow-feathered, snow-hung, snow-laden, snow-lined, snow-loaded,
   snow-mantled, snow-sprinkled, snow-still, snow-tipped, snow-topped,
   snow-white, snowlike, spotless, stainless, swan-white, taintless,
   unblemished, unblotted, uncorrupt, undefiled, unsoiled, unspotted,
   unstained, unsullied, untainted, untarnished, virtuous, white,
   white as snow