Paris green

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A poisonous emerald-green powder, C₄H₆As₆Cu₄O₁₆, used as a pigment, insecticide, and wood preservative.

from The Century Dictionary.

• noun See green.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun copper(II) acetoarsenite, a highly toxic blue-green compound used as a pigment, colorant, insecticide and rodenticide.
• adjective Of a shade of pale green, originally produced with Copper(II) acetoarsenite

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a shade of green tinged with yellow
• noun a toxic double salt of copper arsenate and copper acetate