- Circulating library
- Circulatory system
- Circumlocutory
- Circumstances
- Circumstantial
- Circumstantial evidence
- Circumventive
- Circumventor
- Cirrhosis
- Cirrus
- Cist
- Cite
- Civilian
- Civility
- Civilize
- Claim
- Claimant
- Clam
- Clandestine
- Clank
- Clapper
- Clapping of hands
- Claymore
- Clean off
- Clean slate
- Clean-cut
- Cleanse
- Clear
- Clear off
- Clear water
- Clew
- Click and drag
- Clicktivism
- Climber
- Clinch
- Clinder
- Cling
- Close ranks
- Close shave
- Close-mouthed
- Closed
- Closed fist
- Closely
- Closely related
- Closeness
- Closet
- Closure motion
- Clothe
- Cloud
- Cml
- Co-belligerent
- Co-dining
- Co-owner
- Co-traveller
- Coadjutor
- Coagulated
- Coagulation
- Coal
- Coal gas
- Coalescence
- Coalface
- Coalite
- Cock-a-hoop
- Cock-crest
- Cockatoo
- Cockerel
- Cockernony
- Cockle
- Cocky
- Cocoa
- Coconut leaves
- Coconut oil
- Coconut palm
- Coconut toddy
- Cod
- Coddiwomple
- Coherence
- Coherent
- Coherently
- Cohesion
- Coiffure
- Coinage
- Coincide
- Coincidence
- Coincidental
- Coir fibre
- Coital
- Coitus
- Colander
- Cold
- Cold comfort
- Collectible
- Collecting
- Collection of a part of produce as tax
- Collective
- Collectivize
- Collegial
- Collide
- Collie
- Collinear