- Civil war
- Clash of interests
- Class conscious
- Class-war
- Classic
- Classical
- Classical antiquity
- Classified
- Clatter
- Clause
- Claustrophobic
- Clavicle
- 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
- Cockalarum
- Cockscomb
- Cocksure
- Cocktail
- Coco
- Coconut
- Cocopeat
- Coddle
- Code
- Cognoscente
- Cohabitation
- Cohesively
- Cohort
- Coil
- Coin
- Coin money
- Coiner
- Col
- Cold cuts
- Collective noun
- College
- Collegian
- Colliding
- Collision
- Collision course
- Collusiveness
- Collyrium
- Colocasia
- Comb
- Combative
- Combing
- Come
- Come across
- Come and go
- Come at
- Come to the surface
- Come together
- Come under
- Comely
- Comemorated
- Comet
- Comfort station
- Comical
- Comilona
- Commissary
- Commission
- Commissioned officer
- Commit suicide
- Committal
- Commix
- Commodification
- Commodore
- Common ground
- Companionable
- Companions
- Companionship
- Company
- Comparator
- Compare
- Compared
- Compatible
- Compel
- Compendium
- Cps
- Compliment
- Components
- Comport with
- Composes