| Term | Definition |
| Catch-22 | paradox (contradiction) in an order or regulation that makes people victioms of its provisions, regardless of what they do |
| crocodile tears | false tears; insincere show of grief |
| cross the Rubicon | take a decisive, irrevocable step |
| cry wolf | give alarm without occasion; give a false alarm |
| dog in the manger | person who prevents others from using something her or she cannot use and does not need |
| fifth column | subversive group of civilians working secretly within their own country to turn it over to an invading enemy |