from The American Heritage® Dictionary of the English Language, 4th Edition
- n. See ferrous sulfate.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. Ferrous sulfate.
from the GNU version of the Collaborative International Dictionary of English
- n. Green vitriol, or sulphate of iron; a green crystalline substance, of an astringent taste, used in making ink, in dyeing black, as a tonic in medicine, etc. It is made on a large scale by the oxidation of iron pyrites. Called also ferrous sulphate.
from The Century Dictionary and Cyclopedia
- n. Green vitriol, the sulphate of iron, or ferrous sulphate, FeSO4.7H2O, a salt of a peculiar astringent taste and of various colors, green, gray, yellowish, or whitish, but more usually green.
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.(American Heritage® Dictionary of the English Language, Fourth Edition)