Ver·di·gris n.
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.
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.