Paris green definition by Webster's New World
Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio. Used by arrangement with John Wiley & Sons, Inc.
a poisonous, bright-green powder made by reacting sodium arsenite with copper sulfate and acetic acid: used chiefly as an insecticide
Origin: after Paris
Paris green definition by American Heritage Dictionary
A poisonous emerald-green powder, C4H6As6Cu4O16, used as a pigment, insecticide, and wood preservative.