- cobblers
- CDC
- Comptroller of the Currency
- Census Bureau
- Counterterrorist Center
- CCRC
- Center for Disease Control and Prevention
- CTC
- Casualty Care Research Center
- certainty
- chiffonier
- chest of drawers
- central office
- countinghouse
- carrot family
- Cornaceae
- Connaraceae
- Cunoniaceae
- cunonia family
- communist
- commie
- collectivist
- capitalistic
- conference
- cooperative
- Craspedia
- Conradina
- Conyza
- Chiococca
- Carthamus
- Carduus
- Castilleja
- Clinopodium
- Culver's physic
- Cnicus
- Castilleia
- Crepis
- Culvers physic
- Cichorium
- Chamaemelum
- Chelone
- Chilopsis
- Chrysothamnus
- Conoclinium
- Carlina
- Collinsia
- Cestrum
- Culver's root
- Cotula
- Calycophyllum