[kop-er-uh
s] 
| a bluish-green, crystalline, saline-tasting, water-soluble heptahydrated solid, FeSO4·7H2O, used chiefly in the manufacture of other iron salts, in water purification, fertilizer, inks, pigments, tanning, photography, and in medicine in the treatment of anemia. |
| cop·per·as (kŏp'ər-əs) n. See ferrous sulfate. [Middle English coperose, a metallic sulfate, from Old French, from Medieval Latin cuperōsa, probably short for *aqua cuprōsa, copper water, from Late Latin cuprum, copper; see copper1.] |
| ferrous sulfate n. A greenish crystalline compound, FeSO4·7H2O, used as a pigment, fertilizer, and feed additive, in sewage and water treatment, and as a medicine in the treatment of iron deficiency. Also called copperas. |
