copper

¹cop·per

noun, often attributive \ˈkä-pər\

Definition of COPPER

1

: a common reddish metallic element that is ductile and malleable and is one of the best conductors of heat and electricity — see element table

2

: a coin or token made of copper or bronze

3

chiefly British : a large boiler (as for cooking)

4

: any of a subfamily (Lycaeninae of the family Lycaenidae) of small butterflies with usually copper-colored wings

Origin of COPPER

Middle English coper, from Old English, from Late Latin cuprum copper, from Latin (aes) Cyprium, literally, Cyprian metal

First Known Use: before 12th century

Rhymes with COPPER

bopper, chopper, cropper, dropper, flopper, hopper, lopper, mopper, popper, proper, shopper, stopper, swapper, topper, whopper

²copper

transitive verb

cop·peredcop·per·ing \ˈkä-p(ə-)riŋ\

Definition of COPPER

: to coat or sheathe with or as if with copper

First Known Use of COPPER

1530

Rhymes with COPPER

bopper, chopper, cropper, flopper, mopper, proper, stopper, swapper

³copper

noun

Definition of COPPER

: police officer

Origin of COPPER

²cop

First Known Use: 1846

cop·per

noun , often attrib \ˈkäp-ər\   (Medical Dictionary)

Medical Definition of COPPER

: a common reddish metallic element that is ductile and malleable and one of the best conductors of heat and electricity—symbol Cu; see element table

—cop·pery \ˈkäp-(ə-)rē\ (audio pronunciation) adjective

copper

noun    (Concise Encyclopedia)

Crystalline copper from Michigan—Courtesy of Ted Boente Collection; photograph, John H. Gerard

Metallic chemical element, one of the transition elements, chemical symbol Cu, atomic number 29. Sometimes found in the free state in nature, it is a reddish metal, very ductile and an unusually good conductor of electricity and heat. Most of the world's copper production is used by the electrical industries; the remainder is combined with other metals (e.g., zinc, tin, nickel) to form alloys such as brass, bronze, nickel silver, and Monel. Copper is part of nearly all coinage metals. In compounds copper usually has valence 1 (cuprous) or 2 (cupric). Cuprous compounds include cuprous oxide, a red pigment and a fungicide; cuprous chloride, a catalyst for certain organic reactions; and cuprous sulfide, with a variety of uses. Cupric compounds include cupric oxide, a pigment, decolorizing agent, and catalyst; cupric chloride, a catalyst, wood preservative, mordant, disinfectant, feed additive, and pigment; and cupric sulfate, a pesticide, germicide, feed additive, and soil additive. Copper is a necessary trace element in the human diet and essential to plant growth; in blue-blooded mollusks and crustaceans it plays the same role in hemocyanin as iron does in hemoglobin.