- 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
- Conics
- Conjectural
- Conjecture
- Conjunction of planets
- Conjure
- Conjurer
- Conk
- Connect time
- Conservation
- Conservation biology
- Conservator
- Conservatory
- Considerate
- Consist
- Consistency, consistence
- Consoles
- Consolidate
- Consultant
- Consumed
- Consumer
- Consummation
- Consumptive
- Contact
- Container
- Containing
- Containing 12
- Contemn
- Continuation
- Continuity
- Coolness
- Contractual
- Convalescence
- Convalescent
- Convenience
- Convention
- Conventional
- Conversion
- Convertible
- Convex
- Conveyance
- Cool wind
- Cooler
- Cooper
- Cop out
- Coparcenor
- Coper
- Copier
- Copious
- Copiousness
- Copper plate
- Copper sulphate
- Copper vessel
- Copra
- Corn
- Corn exchange
- Corn heap
- Corn pone