English Reference
noun · adjective · verb

copper

n. · adj. · v.
US /ˈkɑpɝ/ UK /kˈɒpɐ/ cop·per UK spelling copper's, copper's

  1. 01 B1 Intermediate Science

    n.a soft, reddish-brown metal that allows electricity and heat to pass through it easily.

    n.a ductile, malleable metallic element (symbol Cu) with high thermal and electrical conductivity.

    Simple

    Most electrical wires in your home are made of copper because it is a great conductor.

    In context

    The price of copper fluctuated wildly on the global market as industrial demand for new infrastructure increased throughout the decade.

  2. 02 B2 Upper Intermediate British EnglishInformalSlang

    n.a slang word for a police officer.

    n.a colloquial term for a police officer, primarily used in British and Australian English.

    Simple

    The thief ran down the alley when he saw a copper coming around the corner.

    In context

    He spent half his life dodging coppers in the East End before finally deciding to go straight and open a legitimate business.

  3. 03 B2 Upper Intermediate

    n.a reddish-brown color like the metal copper.

    n.a reddish-brown hue resembling the appearance of polished or weathered copper metal.

    Simple

    The autumn leaves turned a beautiful shade of copper before falling to the ground.

    In context

    The interior designer recommended accents of copper and deep teal to create a warm, sophisticated atmosphere in the study.

    reddish brownrusset
  4. 04 B1 Intermediate

    adj.made of copper or having a reddish-brown color.

    adj.composed of the element copper or possessing its characteristic reddish-brown color.

    Simple

    She wore a copper bracelet that she bought at the local craft market.

    In context

    The building was topped with a copper roof that had developed a distinctive green patina over decades of exposure to the elements.

  5. 05 C2 Proficiency TechnicalFormal Technical

    v.to cover something with a thin layer of copper.

    v.to coat, plate, or sheathe an object with a layer of copper.

    Simple

    The artist decided to copper the bottom of the sculpture to protect it from water.

    In context

    The hull was coppered to prevent the growth of marine organisms and to protect the timber from wood-boring worms during long voyages.

This early photography technique produced a single, one-of-a-kind image on a silver-coated piece of copper treated with light-sensitive chemicals.

Smithsonian Magazine· 28 Jul 2026

Where SO-DIMMs have copper contacts across the bottom edge that go into a slot, CAMM has copper contacts spread across one entire side.

Ars Technica· 27 Jul 2026

Etymology 1

The noun is inherited from Middle English coper, copper (“copper ore; copper metal; bronze”), from Old English coper, copor (“copper”), from Late Latin cuprum (“copper”), a contraction of Latin aes Cyprium (literally “Cyprian brass or copper”), ultimately from Ancient Greek Κῠ́προς (Kŭ́pros, “Cyprus”) (a major source of copper during the Near East’s Bronze Age), from the name of a Northwest Semitic goddess from the root כ־ב־ר/ك ب ر (k b r) (“related to being big, large; great; or old”). Doublet of kobo. The adjective is from an attributive use of the noun. The verb is also derived from the noun. cognates * Dutch koper (“copper”) * German Kupfer (“copper”) * Icelandic kopar (“copper”)

Etymology 2

The noun is probably derived from cop (“(informal, dated) to arrest or capture (someone)”) + -er (suffix forming agent nouns), although cop is attested slightly later. The verb is derived from the noun.

Etymology 3

From cop (“ball of thread wound on to a spindle in a spinning machine”) + -er (suffix denoting things relating to the words to which the suffix is attached to).

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

This entry
Origin sem-nwe -
Level C1 · Advanced
Frequency Common
Updated