copperyoudaoicibaDictYouDict[copper 词源字典]
copper: [OE] A major source of copper in the ancient world was the Mediterranean island of Cyprus, so the Romans called it cyprium aes ‘metal of Cyprus’. This became cuprum in late Latin, from which it was borrowed into prehistoric West and North Germanic as *kupar, source of Old English coper. (Copper the slang term for ‘policeman’ [19] is simply the agent noun formed from the verb cop ‘seize’, which probably comes via Old French caper from Latin capere ‘seize, take’, source of English capture.)
[copper etymology, copper origin, 英语词源]
copper (n.1)youdaoicibaDictYouDict
malleable metallic element, Old English coper, from Proto-Germanic *kupar (cognates: Middle Dutch koper, Old Norse koparr, Old High German kupfar), from Late Latin cuprum, contraction of Latin Cyprium (aes) "Cyprian (metal)," after Greek Kyprios "Cyprus" (see Cyprus).

Latin aes originally was "copper," but this was extended to its alloy with tin, bronze, and as this was far more extensively used than pure copper, the word's primary sense shifted to the alloy and a new word evolved for "copper," from the Latin form of the name of the island of Cyprus, where copper was mined. Aes passed into Germanic (which originally did not distinguish copper from its alloys) and became English ore. In Latin, aes was the common word for "cash, coin, debt, wages" in many figurative expressions. Chemical symbol Cu is from cuprum.
copper (n.2)youdaoicibaDictYouDict
"policeman," 1846; agent noun from cop (v.).