- Clarify
- Clarion
- Clasp
- Classical music
- Classical work
- Classify
- Classifying
- Classless
- Classmate
- Classy
- Clavichord
- Cmc
- Clearance
- Clearing house
- Cleave
- 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
- Cock of the walk
- Cock-up
- Cockroach
- Coconut husk
- Coconut scrapes
- Cocoon
- Cod fish
- Codasyl
- Code of conduct
- Codec
- 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
- Compalacency
- Comparative
- Comparatively