- Christian science
- Christianise
- Christianity
- Christians
- Christmas rose
- Christo
- Chromaticity
- Chromatics
- Chromosome
- Chronic
- Chronograph
- Chronologic
- Circuit
- Circulation
- Circumference
- Circumrotation
- Civilised
- Claimed
- Clairaudience
- Clam up
- Clammy
- Clamor
- Clamour
- Clamp down on
- Clap of thunder
- Clay
- Clean down
- Clean from
- Clean hands
- Clean-handed
- Clean-shaven
- Cleanliness
- Cleanness
- Cleverness
- Cliff
- Climbers
- Climbing plant
- Climbing stem
- Clinging
- Clinging steadfastedly on
- Clinical psychology
- 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
- Codex
- Codger
- Coed
- Coefficient
- Coessential
- Coffee break
- Coffee plant
- Coffer
- Cogitate
- Cogitation
- Cogitative
- Cognate
- Cognisance
- Cold storage
- Cold war
- Cold-blooded
- Cold-hearted
- Coleslaw
- Coliform
- Coliseum
- Colitis
- Collaboratively
- Collage
- Collapse
- Collapsible
- Collar beam
- Collectedly
- Comb
- Combative
- Combing
- Come
- Come across
- Come and go
- Come at