- Circular
- Circulate
- Circulating library
- Circulatory system
- Circumlocutory
- Circumstances
- Circumstantial
- Circumstantial evidence
- Circumventive
- Circumventor
- Cirrhosis
- Cirrus
- Cist
- Cite
- Citric acid
- Citronella oil
- City state
- Ciu
- Civet
- Civil case
- Civil engineer
- Civil rights
- Civil service
- Civilian
- Civility
- Civilize
- Claim
- Claimant
- Clam
- Clandestine
- Clank
- Clapper
- Clapping of hands
- Clarion call
- Clarity
- Clash
- Clashing
- Class distinction
- Classicism
- Classroom
- Claustrophobia
- Claviger
- Claw
- Claymore
- Clean off
- Clean slate
- Clean-cut
- Cleanse
- Clear
- Clear off
- Clear water
- Clearly
- Clears
- Cleaver
- Cleft footed
- Clench
- Clenching the fist
- Cleopatra ramases akhnaton tuthankhaman
- Clepsyddra
- Clevage
- Clever person
- Clew
- Click and drag
- Clicktivism
- Climber
- Clinch
- Clinder
- Cling
- Clipper
- Cloaca
- Cloak
- Cloistral
- Close fisted man
- Close ranks
- Close shave
- Close-mouthed
- Closed
- Closed fist
- Closely
- Closely related
- Closeness
- Closet
- Closure motion
- Clothe
- Cloud
- Cloudily
- Cloudiness
- Cloudscape
- Clowder
- Clown
- Cloying
- Clump
- Cluster of lotus blossoms
- Cm
- Cml
- Co-belligerent
- Co-dining
- Co-owner
- Co-traveller
- Coadjutor