The Collaborative International Dictionary of English v.0.48:

Ermine \Er"mine\, n. [OF. ermine, F. hermine, prob. of German
   origin; cf. OHG. harmo, G. hermelin, akin to Lith. szarm?,
   szarmonys, weasel, cf. AS. hearma; but cf. also LL.
   armelinus, armellina, hermellina, and pellis Armenia, the fur
   of the Armenian rat, mus Armenius, the animal being found
   also in Armenia.]
   1. (Zo["o]l.) A valuable fur-bearing animal of the genus
      Mustela (M. erminea), allied to the weasel; the stoat.
      It is found in the northern parts of Asia, Europe, and
      America. In summer it is brown, but in winter it becomes
      white, except the tip of the tail, which is always black.
      [1913 Webster]

   2. The fur of the ermine, as prepared for ornamenting
      garments of royalty, etc., by having the tips of the
      tails, which are black, arranged at regular intervals
      throughout the white.
      [1913 Webster]

   3. By metonymy, the office or functions of a judge, whose
      state robe, lined with ermine, is emblematical of purity
      and honor without stain. --Chatham.
      [1913 Webster]

   4. (Her.) One of the furs. See Fur (Her.)
      [1913 Webster]

   Note: Ermine is represented by an argent field, tufted with
         black. Ermines is the reverse of ermine, being black,
         spotted or timbered with argent. Erminois is the same
         as ermine, except that or is substituted for argent.
         [1913 Webster]

   Ermine moth (Zo["o]l.), a white moth with black spots (esp.
      Yponomeuta padella of Europe); -- so called on account
      of the resemblance of its covering to the fur of the
      ermine; also applied to certain white bombycid moths of
      America.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Ermine \Er"mine\, v. t.
   To clothe with, or as with, ermine.
   [1913 Webster]

         The snows that have ermined it in the winter. --Lowell.
   [1913 Webster]

WordNet (r) 3.0 (2006):

ermine
    n 1: the expensive white fur of the ermine
    2: mustelid of northern hemisphere in its white winter coat
       [syn: ermine, shorttail weasel, Mustela erminea]

Moby Thesaurus II by Grady Ward, 1.0:

172 Moby Thesaurus words for "ermine":
   Australian seal, achievement, alerion, animal charge, annulet,
   argent, armorial bearings, armory, arms, azure, bandeau, bar,
   bar sinister, baton, bearings, bearskin, beaver, beaverette, bend,
   bend sinister, billet, black fox, black marten, black sable,
   blazon, blazonry, bordure, broad arrow, brook mink, buckskin,
   cadency mark, calf, calfskin, canton, cap of dignity,
   cap of maintenance, capeskin, cat, chaplet, charge, chevron, chief,
   chinchilla, chinchillette, coast seal, coat of arms, cockatrice,
   coney, coronet, cowhide, crescent, crest, cross, cross moline,
   crown, deerskin, device, diadem, difference, differencing, doeskin,
   eagle, electric seal, ermines, erminites, erminois, escutcheon,
   falcon, fess, fess point, field, file, flanch, fleece,
   fleur-de-lis, fox, fret, fur, furs, fusil, garland, genet,
   goatskin, great seal, griffin, gules, gyron, hatchment, helmet,
   heraldic device, honor point, impalement, impaling, inescutcheon,
   jaguar, label, lapin, leopard, lion, lozenge, mantling, marmot,
   marshaling, marten, martlet, mascle, merino, metal, mink, mole,
   moleskin, monkey, motto, mullet, muskrat, nombril point, nutria,
   octofoil, or, orb, ordinary, orle, otter, pale, paly, pean, pelts,
   pheon, pigskin, privy seal, purple, purple pall, purpure, quarter,
   quartering, rabbit, rabbitskin, raccoon, regalia, robe of state,
   rod, rod of empire, rose, royal crown, sable, saltire, scepter,
   scutcheon, seal, shagreen, sheepskin, shield, signet, skunk,
   spread eagle, squirrel, subordinary, tenne, tiara, tiger, tincture,
   torse, tressure, triple plume, unicorn, uraeus, vair, vert,
   white fox, wool, wreath, yale