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1. Symbol Cu A ductile, malleable, reddish-brown metallic element that is an excellent conductor of heat and electricity and is widely used for electrical wiring, water piping, and corrosion-resistant parts, either pure or in alloys such as brass and bronze. Atomic number 29; atomic weight 63.546; melting point 1,085°C; boiling point 2,562°C; specific gravity 8.96; valence 1, 2. See Periodic Table.
2. A coin, usually of small denomination, made of copper or a copper alloy.
3. Chiefly British A large cooking pot made of copper or often of iron.
4. Any of various small butterflies of the subfamily Lycaeninae, having predominantly copper-colored wings.
5. A reddish brown.
tr.v. cop·pered, cop·per·ing, cop·pers
1. To coat or finish with a layer of copper.
2. Slang To bet against, as in faro.
[Middle English coper, from Old English, from Late Latin cuprum, from Latin Cyprium (aes), Cyprian (metal), from Cyprius, of Cyprus, from Greek Kuprios, from Kupros, Cyprus.]
A police officer.