| Clapton | A town name meaning farm by a hill. |
| Clarinet | A woodwind instrument with a reed. |
| Clarinetta | A small or diminutive clarinet. |
| Clave | A rhythmic pattern in Latin music. |
| Clef | A symbol used in musical notation. |
| Clementa | A gentle and merciful person. |
| Cleora | One who is bright and famous. |
| Clopin | A name meaning little limp. |
| Cobain | Derived from a place in Wales. |
| Code | A system of signals or rules. |
| Conanina | A small and wise little wolf. |
| Conductor | One who leads an orchestra. |
| Connelly | A name meaning love or hound. |
| Coorg | A region in southern India. |
| Copia | The Latin word for abundance. |
| Core | The central part of anything. |
| Coreopsis | A flower with a seedlike fruit. |
| Corfa | A name meaning a basket or chest. |
| Corfu | A Greek island of the Ionian Sea. |
| Cork | Bark from the cork oak tree. |
| Cornet | A small brass musical instrument. |
| Cornetta | A small horn or musical trumpet. |
| Corsica | A large island in the Mediterranean. |
| Cortana | A name meaning a short sword. |
| Cortex | The outer layer of an organ. |
| Corus | A name meaning a choir or chorus. |
| Corvina | Derived from the Latin for raven. |
| Costanza | A name meaning constant or steady. |
| Cota | A name meaning a small cottage home. |
| Count | A title meaning a noble nobleman. |
| Crater | A bowl shaped volcanic opening. |
| Creta | A name referring to the island Crete. |
| Crius | A name meaning to grow or to create. |
| Crix | A name meaning a sharp crossroads. |
| Crutchie | A name meaning a support or crutch. |
| Cupido | Latin for desire or love. |
| Curumim | Tupi word for a young boy. |
| Cyber | Relating to computer networks. |
| Cybera | A modern name meaning digital. |
| Cygnus | Latin name for the swan star. |