- Chronis
- Chronometer
- Ciborium
- Cicatrice
- Cigar
- Cigarette
- Cilia
- Cinder
- Cinnamomum osmophloeum
- Cinnamon leaf
- Cinnamon tree
- Cipher
- Circa
- Circadian rhythm
- Citric acid
- Citronella oil
- City state
- Ciu
- Civet
- Civil case
- Civil engineer
- Civil rights
- Civil service
- Clarion call
- Clarity
- Clash
- Clashing
- Class distinction
- Classicism
- Classroom
- Claustrophobia
- Claviger
- Claw
- Clearly
- Clears
- Cleaver
- Cleft footed
- Clench
- Clenching the fist
- Cleopatra ramases akhnaton tuthankhaman
- Clepsyddra
- Clevage
- Clever person
- Close ranks
- Close shave
- Close-mouthed
- Closed
- Closed fist
- Closely
- Closely related
- Closeness
- Closet
- Closure motion
- Clothe
- Cloud
- Cml
- Co-belligerent
- Co-dining
- Co-owner
- Co-traveller
- Coadjutor
- Coagulated
- Coagulation
- Coal
- Coal gas
- Coalescence
- Coalface
- Coalite
- Codes
- Codification
- Codifier
- Codify
- Codswallop
- Coeliac
- Coenzyme
- Coercion
- Coexisting
- Coffee-table book
- Coffin
- Cogent
- Cognomen
- Collectible
- Collecting
- Collection of a part of produce as tax
- Collective
- Collectivize
- Collegial
- Collide
- Collie
- Collinear
- Colloquial usage
- Colloquy
- Collywobbles
- Comal
- Comatose
- Comb out
- Combinatorics
- Combined
- Combust
- Come along