- Cloister
- Clop
- Close around
- Close down
- Clouds
- Clove
- Cloven
- Clownish
- Cloze test
- Club
- Cluck
- Clueless
- Clumsily
- Clumsy
- Clunker
- Clutter
- Coals
- Coals to new castle
- Coast
- Coat of arms
- Coated
- Coattails effect
- Cobalt bomb
- Cobble
- Cobbler
- Cobol
- Cobra
- Cocaine
- Cock
- Cockalarum
- Cockscomb
- Cocksure
- Cocktail
- Coco
- Coconut
- Cocopeat
- Coddle
- Code
- Cognoscente
- Cohabitation
- Cohesively
- Cohort
- Coil
- Coin
- Coin money
- Coiner
- Col
- Cold cuts
- Cold storage
- Cold war
- Cold-blooded
- Cold-hearted
- Coleslaw
- Coliform
- Coliseum
- Colitis
- Collaboratively
- Collage
- Collapse
- Collapsible
- Collar beam
- Collectedly
- Colon
- Colonial
- Colonialism
- Colonization
- Colonize
- Colophon
- Colophony
- Colorectal
- Colour bar
- Colour printing
- Colouring
- Colt
- Come into ones own
- Come out
- Come through
- Come to grief
- Come to his senses
- Commingle
- Come to the surface
- Come together
- Come under
- Comely
- Comemorated
- Comet
- Comfort station
- Comical
- Comilona
- Commissary
- Commission
- Commissioned officer
- Commit suicide
- Committal
- Commix
- Commodification
- Commodore
- Common ground
- Common sense
- Communalism