- Chronometer
- Circuitous
- Circular
- Circulate
- Circulating library
- Circulatory system
- Circumlocutory
- Circumstances
- Circumstantial
- Circumstantial evidence
- Circumventive
- Circumventor
- Cirrhosis
- Cirrus
- Cist
- Cite
- Clarion call
- Clarity
- Clash
- Clashing
- Class distinction
- Classicism
- Classroom
- Claustrophobia
- Claviger
- Claw
- Clew
- Click and drag
- Clicktivism
- Climber
- Clinch
- Clinder
- Cling
- Cloudily
- Cloudiness
- Cloudscape
- Clowder
- Clown
- Cloying
- Clump
- Cluster of lotus blossoms
- Cm
- Cock-a-hoop
- Cock-crest
- Cockatoo
- Cockerel
- Cockernony
- Cockle
- Cocky
- Cocoa
- Coconut leaves
- Coconut oil
- Coconut palm
- Coconut toddy
- Cod
- Coddiwomple
- Cold turkey
- Cold water
- Coldish
- Collaborate
- Collaborative
- Collar bone
- Collate
- Collation
- Colleague
- Colonitis
- Colony
- Colorful
- Colors
- Colossal
- Colostrums
- Colour box
- Colourist
- Colours
- Column
- Columnar
- Com
- Com and go
- Coming on
- Comity
- Command
- Commandant
- Commenator
- Commencement
- Commend
- Commendation
- Commerce
- Commercially
- Companion
- Comparisons are odious
- Compartment
- Compassionate
- Compendious
- Compersion
- Competence
- Competency
- Compress
- Compulsive
- Compulsory
- Computer