ETYM French vert-de-gris, apparently from verd, vert, green + de of + gris gray, but really a corruption of Late Lat. viride aeris (equivalent to Latin aerugo), from Latin viridis green + aes, aeris, brass. Related to Verdant, and Ore.
Greenish copper coating.
1. 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.
Green-blue coating of copper ethanoate that forms naturally on copper, bronze, and brass. It is an irritating, greenish, poisonous compound made by treating copper with ethanoic acid, and was formerly used in wood preservatives, antifouling compositions, and green paints.