- Cold-blooded
- Cold-hearted
- Coleslaw
- Coliform
- Coliseum
- Colitis
- Collaboratively
- Collage
- Collapse
- Collapsible
- Collar beam
- Collectedly
- Colon
- Colonial
- Colonialism
- Colonization
- Colonize
- Colophon
- Colophony
- Colorectal
- Colour bar
- Colour printing
- Colouring
- Colt
- Come into ones own
- Come out
- Come through
- Come to grief
- Come to his senses
- Commingle
- Coming to blows
- Comma bacillus
- Command-ed
- Commander-in-chief
- Commandments
- Commando
- Commandos
- Comme il faut
- Commemorate
- Commemoration
- Commence
- Commendable
- Commensurable
- Commensurable ness
- Commentary
- Commentate, commentator
- Commercial
- Commiseration
- Common sense
- Communalism
- Communicable
- Communication
- Communication satellite
- Comorbid
- Compiling
- Complacence
- Complete eradication
- Complete figure
- Completed
- Completeness
- Completion
- Complex
- Complexion
- Complexity
- Compliance
- Compliant
- Compressed air
- Comprising
- Compunction
- Compute
- Computer graphics
- Comrade
- Comsat
- Con man
- Concatenate
- Concatenation
- Concede
- Conciliator
- Concisely
- Conclave
- Concluded
- Concluding
- Concreteness, concretion
- Concupiscent
- Concussion
- Condemn to
- Condemnatory
- Condemned by
- Confabulate
- Confederate
- Confessant
- Confessional
- Confined at the surface
- Confinement
- Confirm
- Confiscating
- Congressional
- Congressman
- Congruity
- Conically