From Longman Dictionary of Contemporary Englishiridiumi‧rid‧i‧um /ɪˈrɪdiəm/ noun [uncountable] HCEMHa hard and very heavy metal that is combined with platinum to make jewellery and is used in scientific instruments. It is a chemical element: symbol Ir
Examples from the Corpus
iridium• Like Green's compound, this iridium compound contains two hydrogen atoms that can be eliminated by light.Origin iridium (1800-1900) Latin iris ( → IRIS); because when it becomes liquid in a particular acid, it shows the colors of the rainbow 