copper

1. (uncountable) A reddish-brown, malleable, ductile metallic element with high electrical and thermal conductivity, symbol Cu, and atomic number 29.Examples: "Trump’s July 8 announcement of a 50% tariff on copper imports beginning August 1 sent prices surging 13% in one day, up to a record high of $5.69 per pound."uncountable

2. (countable, dated) Any of various specialized items that are made of copper, where the use of copper is either traditional or vital to the function of the item.Examples: "Coppers are generally good for a year, if the battery is carefully attended […]"; "Some coppers come already tinned. I didn't buy mine, so they surely were not tinned."; "Coppers are not consumed, and their life depends largely on the manner in which they are used."countabledated

3. (countable, dated) Any of various specialized items that are made of copper, where the use of copper is either traditional or vital to the function of the item.Examples: "I had in my pocket a handful of copper money, three or four silver dollars, and five pistoles in gold. As he proceeded I began to soften, and concluded to give the coppers."; ""I don't want to spoil any comparison you are going to make," said Jim, "but I was at Winchester and New College." ¶ "That will do," said Mackenzie. "I was dragged up at the workhouse school till I was twelve. Then I ran away and sold papers in the streets, and anything else that I could pick up a few coppers by—except steal.[…].""countabledated

4. (countable, dated) Any of various specialized items that are made of copper, where the use of copper is either traditional or vital to the function of the item.Examples: "Mum would heat the water in a copper in the kitchen and transfer it to the tin bath."; "I explain that socks can’t be boiled up in the copper with the sheets and towels or they shrink."; "When the water in the copper boils, the arsenic and tartar, well pounded, is put into it, and kept boiling till the liquor is reduced to about half."AustraliaUKcountabledateduncountable

5. (entomology) Any of various lycaenid butterflies with copper-coloured upperwings, especially those of the genera Lycaena and Paralucia.countableuncountable