Cat’s whiskers: Again it means something that is excellent.

Catch as catch can: To try and get something in anyway possible.

Catch hell: To get into trouble.

Champ at the bit: To be very eager to accomplish something.

Champing at the bit: To be impatient for something.

Change horses in midstream: To have a change of plans or leader/workers in the middle of some work or act, which can prove to be a risky act.

Change track: To change your mode of action or your mind for doing something.

Change your tune: To change the way someone talks, most likely due to a change of thinking.

Chapter and verse: To know something so well that each detail, such as the chapter and verse of something, can be quoted. Chase rainbows: To try and do something that is impossible to attain or achieve. Chase your tail: To make a lot of effort to do something that is unproductive.

Cheap as chips: An inexpensive thing.

Cheap shot: A very rude criticism.

Cheat death: To cheat death is to narrowly escape death, accident or a great mishap.

Cherry pick: To choose only those things that suit people or their stand, ignoring those that go against them.

Chew on a bone: To think about something absorbedly and carefully.

Chew the cud: To ponder over something.

Chickenfeed: Something irrelevant, or a very small amount of money.

Chop and change: If things chop and change, they keep changing, often unexpectedly.

Clean break: To break away completely from something.

Clean your clock: To beat someone decisively in a competition or contest.

Clear as mud: Very unclear.

Climb on the bandwagon: To do something because everyone else is doing it too.

Cloud cuckoo land: To have very unrealistic and impractical ideas and plans.

Cloud on the horizon: To foresee a problem.

— Ahzam Ahmed