Source : Webster's Revised Unabridged Dictionary (1913)

Verdigris \Ver"di*gris\, n. [F. vert-de-gris, apparently from
   verd, vert, green + de of + gris gray, but really a
   corruption of LL. viride aeris (equivalent to L. aerugo),
   from L. viridis green + aes, aeris, brass. See {Verdant}, and
   2d {Ore}.]
   1. (Chem.) A green poisonous substance used as a pigment and
      drug, obtained by the action of acetic acid on copper, and
      consisting essentially of a complex mixture of several
      basic copper acetates.

   2. The green rust formed on copper. [Colloq.]

   Note: This rust is a carbonate of copper, and should not be
         confounded with true verdigris. --U. S. Disp.

   {Blue verdigris} (Chem.), a verdigris having a blue color,
      used a pigment, etc.

   {Distilled verdigris} (Old Chem.), an acid copper acetate; --
      so called because the acetic acid used in making it was
      obtained from distilled vinegar.

   {Verdigris green}, clear bluish green, the color of
      verdigris.