copperas

[ kop-er-uhs ]

noun

, Chemistry.

1. ferrous sulfate.

copperas

/ ˈkɒpərəs /

noun

1. See ferrous sulphate
   a less common name for ferrous sulphate

Word History and Origins

Origin of copperas¹

1400–50; late Middle English coperas, variant of Middle English coperose < Medieval Latin ( aqua ) cuprōsa copperish (water). See copper ¹, -ose ¹

Word History and Origins

Origin of copperas¹

C14: coperose, via Old French from Medieval Latin cuperosa, perhaps originally in the phrase aqua cuprosa copper water

Example Sentences

Logwood dyes lilac, or pink; to turn red hackles brown, boil them in copperas.

From Project Gutenberg

Copper dissolved in the vitriolic acid forms crystals of a blot colour, called blue copperas.

From Project Gutenberg

Boil the logwood for 30 minutes in a gallon of water, and then add the copperas and lampblack.

From Project Gutenberg

The hypo., when thus affected with the copperas, appears also to throw a mist over the picture, which new hypo.

From Project Gutenberg

When such is the case, only about 1⁄6 or 1⁄7th of their weight of copperas should be employed.

From Project Gutenberg