| Term | Definition |
| cache | A hiding place; stash pile |
| cacophony | An unpleasant, jarring noise |
| calumny | A false and harmful accusation; misrepresentation |
| cantankerous | Having a difficult, stubborn, uncooperative personality |
| captious | The tendency to mention the faults; intending to confuse in an argument |
| cataclysmic | Extremely destructive; catastrophic |
| catalyst | Some that speeds up and promotes significant changes, without being affected by any consequences |
| caucus | A restricted committee within a political party; a private committee conference |
| caustic | Biting; sarcastic |
| cede | To surrender possession of something |
| celerity | Speed; haste |
| censorious | Tending to accuse and condemn; critical |
| certitude | Assurance |
| cessation | A temporary or permanent halt or pause |
| chary | Vigilant, wary; very shy |
| chimerical | Whimsical; imaginary, impossible |
| circuitous | Indirect; roundabout |
| circumvent | To avoid; go around |
| cloying | Sappy; sickly sweet; excessive |
| coagulate | To clot; cause to thicken |
| cogent | Forceful logically; compelling or convincing |
| colloquial | Informal wording or speech |
| commute | To change a punishment to a less severe one. (I. "Scooter" Libby) |
| complacent | Smug; self-satisfied |
| compliant | Yielding; cooperative |
| concomitant | Existing or occuring alongside something else |
| concord | Agreement |
| condole | To grieve for; to express sympathy |
| conflagration | Large, destructive fire |
| confluence | The act of two things flowing together; the junction or meeting place where the two meet |
| consanguineous | Having the same ancestry; blood-related |
| consternation | An increse of fear/dismay |
| constituent | Component/part; citizen, voter |
| constraint | Something that restricts or stops within bounds |
| contemptuous | Scornful; expressing contempt |
| contentious | Quarrelsome; disagreeable; uncooperative |
| contiguous | Sharing a boundary; neighboring |
| continence | Self-control; restraint |
| convalesce | To gradually recuperate from an illness/injury |
| convergence | The state when several substances combine or join together |
| coquette | A flirtatious woman |
| coterie | An close group of people with a similar purpose or intention |
| countervail | To act or react with equal force |
| covert | Secretive, not openly shown |
| cull | To select; single out |
| cumulative | Increasing; collective |
| curt | Abrupt; terse; short with words |