ferrous sulphate

noun

1. an iron salt with a saline taste, usually obtained as greenish crystals of the heptahydrate, which are converted to the white monohydrate above 100°C: used in inks, tanning, water purification, and in the treatment of anaemia. Formula: FeSO 4Systematic name: iron (II) sulphate Also called: copperas, green vitriol