- Coalition
- Coat hanger
- Coaxing
- Cob
- Cobweb
- Cobwebs
- Cock and bull story
- Cock eye
- Codes
- Codification
- Codifier
- Codify
- Codswallop
- Coeliac
- Coenzyme
- Coercion
- Coexisting
- Coffee-table book
- Coffin
- Cogent
- Cognomen
- Cold turkey
- Cold water
- Coldish
- Collaborate
- Collaborative
- Collar bone
- Collate
- Collation
- Colleague
- Colonitis
- Colony
- Colorful
- Colors
- Colossal
- Colostrums
- Colour box
- Colourist
- Colours
- Column
- Columnar
- Com
- Com and go
- Come into force
- Come on
- Come thick and fast
- Come to aid
- Come to an end
- Come to blows
- Come to life
- Come to light
- Coming on
- Comity
- Command
- Commandant
- Commenator
- Commencement
- Commend
- Commendation
- Commerce
- Commercially
- Common-mans
- Commonalty
- Communal
- Communalist
- Communicate
- Communist army
- Community health centre
- Commutator
- Commuter
- Compact
- Competitive
- Compile
- Compiler
- Complain
- Complementary
- Complementary operation
- Completely
- Compress
- Compulsive
- Compulsory
- Computer science
- Con
- Concealed
- Concede defeat
- Conceit
- Conciseness
- Concocted
- Concomitancy
- Concordance
- Concourse
- Concrete
- Concretize
- Concubine
- Concurrent
- Condemners
- Condemning
- Condensed
- Conditionally
- Conducive