copper

¹ American  

[kop-er] / ˈkɒp ər /

noun

1. a malleable, ductile, metallic element having a characteristic reddish-brown color: used in large quantities as an electrical conductor and in the manufacture of alloys, as brass and bronze. Cu; 63.54; 29; 8.92 at 20°C.

2. a metallic reddish brown.

3. a coin composed of copper, bronze, or the like, as the U.S. cent or the British penny.

4. any of several butterflies of the family Lycaenidae, as Lycaena hypophleas American copper, having copper-colored wings spotted and edged with black.

5. a container made of copper.

6. a tool partly or wholly made of copper.

   a soldering copper.

7. British. a large kettle, now usually made of iron, used for cooking or to boil laundry.

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adjective

1. made of copper.

   copper kettles.

2. reddish-brown; coppery.

   The copper sun sank into the sea.

verb (used with object)

1. to cover, coat, or sheathe with copper.

2. Informal. hedge.

copper ² American  

[kop-er] / ˈkɒp ər /

noun

Slang.

1. a police officer.

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copper ¹ British  

/ ˈkɒpə /

noun

1. Often shortened to: cop.  a slang word for policeman

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copper ² British  

/ ˈkɒpə /

noun

1. 1. a malleable ductile reddish metallic element occurring as the free metal, copper glance, and copper pyrites: used as an electrical and thermal conductor and in such alloys as brass and bronze. Symbol: Cu; atomic no: 29; atomic wt: 63.546; valency: 1 or 2; relative density: 8.96; melting pt: 1084.87±+0.2°C; boiling pt: 2563°C

   2. ( as modifier )

      a copper coin

2. 1. the reddish-brown colour of copper

   2. ( as adjective )

      copper hair

3. informal any copper or bronze coin

4. a large vessel, formerly of copper, used for boiling or washing

5. any of various small widely distributed butterflies of the genera Lycaena, Heodes, etc, typically having reddish-brown wings: family Lycaenidae

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verb

1. (tr) to coat or cover with copper

copper Scientific  

/ kŏp′ər /

1. A reddish-brown, ductile, malleable metallic element that is an excellent conductor of heat and electricity. It is widely used for electrical wires, water pipes, and rust-resistant parts, either in its pure form or in alloys such as brass and bronze. Atomic number 29; atomic weight 63.546; melting point 1,083°C; boiling point 2,595°C; specific gravity 8.96; valence 1, 2.

2. See Periodic Table See Note at element

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Other Word Forms

• coppery adjective

Etymology

Origin of copper¹

First recorded before 1000; Middle English coper, copper, Old English coper, copor (cognate with Old Norse koparr, German Kupfer ), from Late Latin cuprum, for Latin ( aes ) Cyprium “(metal) from Cyprus”

Origin of copper²

First recorded in 1830–40; perhaps cop ² + -er ¹

Explanation

Copper is a reddish-gold colored metal that's commonly used in electrical wires and plumbing. Your grandmother might make her famous chocolate caramel sauce in a shiny copper pot. Before 1983, pennies were 95 percent copper. Today, they're almost entirely zinc (a less expensive metal), coated with a thin copper plating. They look the same, but the older coins are quite a bit heavier. Copper is a good conductor of heat and electricity, which is why it's used for both fancy cookware and wires. You can also use copper for things that have a similar color: "His copper curls make him stand out from the other choir members."

Example Sentences

Plus, the transition to next-generation 1.6T copper cables could drive about 50% higher average sales prices, he added.

From MarketWatch • Apr. 11, 2026

Additionally, Marvell is a play on optical networking, an area that’s becoming increasingly interesting as customers look for faster, higher-bandwidth and lower-latency alternatives to traditional copper wiring in AI data centers.

From MarketWatch • Apr. 10, 2026

Jefferies analysts recommend investing in copper miners, such as Freeport-McMoRan, due to copper’s strong correlation with economic activity and AI demand.

From Barron's • Apr. 10, 2026

Gold is a bit trickier than copper since it’s more of a speculative bet and is not tied to industrial demand the way that copper is.

From Barron's • Apr. 10, 2026

A gagana—a bird with an iron beak and copper claws—dead in its nest with its young.

From "Impossible Creatures" by Katherine Rundell

Related Words

• constable
• detective
• man
• officer
• patrolman
• patrolwoman
• police
• policewoman