# copper vs cotter

> English confusable word pair

## The two words

### copper
*noun · IPA /ˈkɒpə/ · frequency rank #4,515*
A reddish-brown metallic chemical element (symbol Cu) with the atomic number 29; also, the metal made up of this element.

### cotter
*noun · IPA /kɒtə/ · frequency rank #37,401*
A pin or wedge inserted through a slot to hold machine parts together.

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/vs/copper-vs-cotter