Source : Webster's Revised Unabridged Dictionary (1913)

Snow \Snow\, n. [OE. snow, snaw, AS. sn[=a]w; akin to D. sneeuw,
   OS. & OHG. sn[=e]o, G. schnee, Icel. sn[ae]r, snj[=o]r,
   snaj[=a]r, Sw. sn["o], Dan. snee, Goth. snaiws, Lith.
   sn["e]gas, Russ. snieg', Ir. & Gael. sneachd, W. nyf, L. nix,
   nivis, Gr. acc. ni`fa, also AS. sn[=i]wan to snow, G.
   schneien, OHG. sn[=i]wan, Lith. snigti, L. ningit it snows,
   Gr. ni`fei, Zend snizh to snow; cf. Skr. snih to be wet or
   sticky. [root]172.]
   1. Watery particles congealed into white or transparent
      crystals or flakes in the air, and falling to the earth,
      exhibiting a great variety of very beautiful and perfect
      forms.

   Note: Snow is often used to form compounds, most of which are
         of obvious meaning; as, snow-capped, snow-clad,
         snow-cold, snow-crowned, snow-crust, snow-fed,
         snow-haired, snowlike, snow-mantled, snow-nodding,
         snow-wrought, and the like.

   2. Fig.: Something white like snow, as the white color
      (argent) in heraldry; something which falls in, or as in,
      flakes.

            The field of snow with eagle of black therein.
                                                  --Chaucer.

   {Red snow}. See under {Red}.

   {Snow bunting}. (Zo["o]l.) See {Snowbird}, 1.

   {Snow cock} (Zo["o]l.), the snow pheasant.

   {Snow flea} (Zo["o]l.), a small black leaping poduran
      ({Achorutes nivicola}) often found in winter on the snow
      in vast numbers.

   {Snow flood}, a flood from melted snow.

   {Snow flower} (Bot.), the fringe tree.

   {Snow fly}, or {Snow insect} (Zo["o]l.), any one of several
      species of neuropterous insects of the genus {Boreus}. The
      male has rudimentary wings; the female is wingless. These
      insects sometimes appear creeping and leaping on the snow
      in great numbers.

   {Snow gnat} (Zo["o]l.), any wingless dipterous insect of the
      genus {Chionea} found running on snow in winter.

   {Snow goose} (Zo["o]l.), any one of several species of arctic
      geese of the genus {Chen}. The common snow goose ({Chen
      hyperborea}), common in the Western United States in
      winter, is white, with the tips of the wings black and
      legs and bill red. Called also {white brant}, {wavey}, and
      {Texas goose}. The blue, or blue-winged, snow goose ({C.
      c[oe]rulescens}) is varied with grayish brown and bluish
      gray, with the wing quills black and the head and upper
      part of the neck white. Called also {white head},
      {white-headed goose}, and {bald brant}.

   {Snow leopard} (Zool.), the ounce.

   {Snow line}, lowest limit of perpetual snow. In the Alps this
      is at an altitude of 9,000 feet, in the Andes, at the
      equator, 16,000 feet.

   {Snow mouse} (Zo["o]l.), a European vole ({Arvicola nivalis})
      which inhabits the Alps and other high mountains.

   {Snow pheasant} (Zo["o]l.), any one of several species of
      large, handsome gallinaceous birds of the genus
      {Tetraogallus}, native of the lofty mountains of Asia. The
      Himalayn snow pheasant ({T. Himalayensis}) in the
      best-known species. Called also {snow cock}, and {snow
      chukor}.

   {Snow partridge}. (Zo["o]l.) See under {Partridge}.

   {Snow pigeon} (Zo["o]l.), a pigeon ({Columba leuconota})
      native of the Himalaya mountains. Its back, neck, and rump
      are white, the top of the head and the ear coverts are
      black.

   {Snow plant} (Bot.), a fleshy parasitic herb ({Sarcodes
      sanguinea}) growing in the coniferous forests of
      California. It is all of a bright red color, and is fabled
      to grow from the snow, through which it sometimes shoots
      up.

Source : WordNet®

snow line
     n : the line on a mountain above which there is perpetual snow
         and ice