1714: copper metal Aug 24, 2019
While 'copper' for 'policeman' might not be related to metal, the history of the term for a metal is much richer. The word may ultimately come from Latin in the form of 'cuprum', but the whole thing comes from Cyprus, insofar as that Latin was a contraction of 'Cyprium aes': Cypriot metal. In fact, the first ever man-made metal alloy, 'bronze' is made partly from copper, and was originally made in that part of the world. It was so common that the words for 'copper', 'bronze', or even metal objects— particularly cash coins—were at times indistinguishable in Latin, simply referred to as 'aes'. Eventually 'cuprum' meant the distinct copper we know today, and 'aes' became 'ore' when it entered English.