Ⓒ

Symbol

 * 1)  an unidentifiable/indeterminate consonant
 * 2)  copper (Daltonian symbol)
 * Technically, this should be typeset as a black 'C' in a red circle.

Related terms

 * 🄫
 * 🅮
 * 🄯
 * 🅭
 * 🄲
 * 🅲
 * See for uses of a letter inside a circle.