From Longman Dictionary of Contemporary Englishverdigrisver‧di‧gris /ˈvɜːdəɡriː, -ɡriːs $ ˈvɜːr-/ noun [uncountable] HCMa greenish-blue substance that sometimes appears on copper or brass
Examples from the Corpus
verdigris• Many displayed the malign green of corruption, the verdigris of spiritual gangrene.• The latter needed a polish, having become tarnished and covered with verdigris.Origin verdigris (1300-1400) Old French vert de Grice “green of Greece” 