blue vitriol: Meaning and Definition of

blue' vit'riol

Pronunciation: [key]
— Chem., Mineral. Chem.,Mineral.
  1. a salt, copper sulfate, CuSO&multiplydot;5HO, occurring naturally as large transparent, deep-blue triclinic crystals, appearing in its anhydrous state as a white powder: used chiefly as a mordant, insecticide, fungicide, and in engraving. Also called
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.