- Clef
- Cleft palate
- Clematis
- Clerical
- Clerk
- Clever fellow
- Clever man
- Cleverish
- Cleverly
- Clinker
- Clinquant
- Clipboard
- Clique
- Cliquish
- Clitic
- clitoridectomy
- Clitoris
- Clock
- Clockwise
- Clog
- Clogging
- Clone
- Clonk
- Close
- Close in
- Co-action
- Co-brother
- Co-brother-in-law
- Co-extensive
- Co-habiting
- Co-student
- Coadjutant
- Coal field
- Coal-black
- Coalesce
- Coalmine
- Coarse sand
- Coarsen
- Coarseness
- Coast of coromandal
- Coastal
- Coaster
- Coastline
- Cobbler-smith
- Coca cola
- Coccinia grandis
- Coccyx
- Cochin
- Cock crow
- Codeine
- Coercive
- Coeval
- Coexistence
- Coffee
- Coffee house
- Cog
- Cognition
- Cognitive
- Cognizance
- Cognizant
- Cold shoulder
- Cold sore
- Coldly
- Coldness
- Colic
- Collaborator
- Collagen
- Collateral
- Collect
- Collectable
- Colonel
- Coloration
- Colorless
- Colour
- Colouration
- Coloured
- Colourful
- Colourless
- Colporteur
- Colubrine
- Columnist
- Come into
- Come into power
- Come of
- Come of well
- Come out of ones shell
- Come short of
- Come to ahead
- Comity of nations
- Comletion
- Comma
- Commanding
- Commandment
- Commenced
- Commensalism
- Comment
- Commiserate
- Common salt
- Commonly
- Commonness