- Conditional
- Conditional probability
- Condo lent
- Condominium
- Conduct
- Cone off
- Confiscator
- Conflagration
- Conflict
- Conflicting
- Confluent
- Conform to
- Confound
- Confront
- Confronting
- Confuse with
- cryptocurrency
- Congenital heart defects
- Congeries
- Congest
- Conglomerate
- Conglomeration
- Conglutinate
- 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
- Cornal desire
- Cornea
- Cornelian
- Cornered
- Cornet
- Cornucopia
- Corolla
- Corona
- Coronary artery
- Coronary thrombosis
- Coronation
- Corrugate
- Corsage
- Corselet
- Coruscation
- Coryza
- Cosmetic preparation
- Cosmogonal suktha
- Cosmography
- Cosmological
- Cosmology
- Coumarone
- Counseller
- Counselling
- Countdown
- Counter plea
- Counter-acting
- Counter-intelligence