| Term | Definition |
| clairvoyant | having ESP, psychic |
| clamor | to make a noisy outcry; a noisy outcry |
| clandestine | secretive |
| clemency | merciful leniency |
| cloister | to confine, seclude |
| coalesce | to grow together or cause to unite as one |
| coddle | to baby, treat indulgently |
| coerce | to compel by force or intimidation |
| cogent | logically forceful, compelling, convincing |
| coherent | intelligible, lucid, understandable |
| collateral | accompanying |
| colloquial | characteristic of informal speech |
| collusion | collaboration, complicity, conspiracy |
| commensurate | proportional |
| commodious | roomy, spacious |
| communicable | transmittable |
| commute | to change a penalty to a less severe one |
| compensate | to repay or reimburse |
| complacent | self-satisfied, smug |
| complement | to complete, perfect |
| compliant | submissive and yielding |
| complicity | knowing partnership in wrongdoing |
| compunction | feeling of uneasiness cause by guilt or regret |
| concave | curving inward |
| concede | to yield, admit |
| conciliatory | overcoming distrust or hostility |
| concur | to agree |
| condone | to pardon or forgive; overlook, justify, or excuse a fault |
| conduit | tube, pipe, or similar passage |
| conflagration | big, destructive fire |
| confound | to baffle, perplex |
| congeal | to become thick or solid, as a liquid freezing |
| congenial | similar in tastes and habits |
| conglomerate | collected group of varied things |
| conjecture | speculation, prediction |
| conscientious | governed by conscience; careful and thorough |
| consecrate | to declare sacred; dedicate to a goal |
| consensus | unanimity, agreement of opinion or attitude |
| consolation | something providing comfort or solace for a loss or hardship |
| consolidate | to combine, incorporate |
| constrained | forced, compelled; confined, restrained |
| construe | to explain or interpret |
| contentious | quarrelsome, disagreeable, belligerent |
| continence | self-control, self-restraint |
| contravene | to contradict, deny, act contrary to |
| contrite | deeply sorrowful and repentant for a wrong |
| conundrum | riddle, puzzle or problem with no solution |
| convalescence | gradual recovery after an illness |
| convene | to meet, come together, assemble |
| conventional | typical, customary, commonplace |