[ 'vɪtrɪəl ]
■ noun
1》 archaic or literary sulphuric acid.
↘in names of metallic sulphates, e.g. blue ~ (copper sulphate) and green ~ (ferrous sulphate).
2》 extreme bitterness or malice.
Origin
ME (denoting the sulphate of various metals): from OFr., or from med. L. ~um , from L. vitrum 'glass'.