Origin of copperas
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for copperas
It was black, but the copperas would eat the paper after a while.The Story of Young Abraham Lincoln
Alum and copperas have been known in the Highlands long ages.
Put the wool into this for 1/2 hour; then return it into the alum and copperas for 10 to 15 minutes.
We're goin' up to Copperas Creek and there ain't a thing in that.Mitch Miller
Edgar Lee Masters
The amount of copperas should be from one and a half to twice that of the indigo.The Dyeing of Cotton Fabrics
- a less common name for ferrous sulphate
C14: coperose, via Old French from Medieval Latin cuperosa, perhaps originally in the phrase aqua cuprosa copper water