| Term | Definition |
| chasm | a deep, gaping hole; a gorge |
| chastise | to inflict punishment on; to discipline |
| chicanery | trickery; deceitfulness; artifice, especially legal or political |
| chimera | an illusion; a foolish fancy |
| choleric | hot-tempered; quick to anger |
| chronic | constant; lasting a long time; inveterate |
| chronicle | a record of events in order of time; a history |
| circuitous | roundabout; not following a direct path |
| circumlocution | an indirect expression; use of wordy or evasive language |
| circumscribe | to draw a line around; to set the limits; to define; to restrict |
| circumspect | cautious |
| circumvent | to frustrate as though by surrounding |
| civil | polite; civilized; courteous |
| clemency | mercy; forgiveness; mildness |
| cliché | an overused saying or idea |
| clique | an exclusive group bound together by some shared quality or interest |
| coalesce | to come together as one; to fuse; to unite |
| coerce | to force someone to do or not to do something |
| cogent | powerfully convincing |
| cognitive | dealing with how we know the world around us through our senses; mental |
| cognizant | aware; conscious |
| coherent | holding together; making sense |
| colloquial | conversational; informal in language |
| collusion | conspiracy; secret cooperation |
| commensurate | equal; proportionate |
| compelling | forceful; causing to yield |
| compendium | a summary; an abridgment |
| complacent | self-satisfied; overly pleased with oneself; contented to a fault |
| complement | to complete or fill up; to be the perfect counterpart |
| complicity | participation in wrongdoing; the act of being an accomplice |
| comprehensive | covering or including everything |
| comprise | to consist of |
| conciliatory | making peace; attempting to resolve a dispute through goodwill |
| concise | brief and to the point; succint |