Definition of "verdigris" []

• A blue or green powder consisting of basic cupric acetate used as a paint pigment and fungicide. (noun)
• A green patina or crust of copper sulfate or copper chloride formed on copper, brass, and bronze exposed to air or seawater for long periods of time. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "In the same way they put in plates of copper and make verdigris, which is called "aeruca.""
• "The trace of tarnished copper, commonly called verdigris, poisoned the wholesome draught; a minute dose administered by stealth did incalculable mischief."
• "There is a school of thought that says the alchemists mistook vitriol for verdigris, which is copper (II) acetate."