1) A word commonly used in Yorkshire for ferrous sulphate, also called ‘green copperas’ or ‘green vitriol’.
It was imported in the fifteenth century but produced locally soon afterwards: 1463 1 C lib’ coperose, Hull
1577 Two pounds grene copperas, viijd, Richmond
1616 coporas and galles, Brandsby
1663 12li coperose, 1s, Selby. See NH159-61.