verdigris
    n 1: a blue or green powder used as a paint pigment [syn:
         verdigris, cupric acetate]
    2: a green patina that forms on copper or brass or bronze that
       has been exposed to the air or water for long periods of time
    v 1: color verdigris

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.
      [1913 Webster]

   2. The green rust formed on copper. [Colloq.]
      [1913 Webster]

   Note: This rust is a carbonate of copper, and should not be
         confounded with true verdigris. --U. S. Disp.
         [1913 Webster]

   Blue verdigris (Chem.), a verdigris having a blue color,
      used as 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.
      [1913 Webster]

Verdigris \Ver"di*gris\, v. t.
   To cover, or coat, with verdigris. [R.] "An old verdigrised
   brass bugle." --Hawthorne.
   [1913 Webster]