verdigris
noun /ˈvɜːdɪɡriː/, /ˈvɜːdɪɡriːs/
/ˈvɜːrdɪɡriː/, /ˈvɜːrdɪɡriːs/
[uncountable]- the green substance that forms, for example on roofs, when copper reacts with the airWord OriginMiddle English: from Old French verte-gres, earlier vert de Grece ‘green of Greece’.