copperas noun.
['kɒp(ǝ)rǝs] LME.[Old & mod. French couperose from medieval Latin cup(e)rosa lit. 'flower of copper', ult. from late Latin cupri- combining form of Latin cuprum copper + rosa ROSE noun, after Greek khalkanthon.]Ferrous sulphate heptahydrate, FeSO
47H2O, a green crystalline compound used in inks and pigments and in medicine. Formerly also, the sulphate of copper or zinc.
blue copperas copper sulphate. green copperas ferrous sulphate heptahydrate. white copperas zinc sulphate.
Comb.:
copperas-stone marcasite. [TahlilGaran] English Dictionary ▲