Can't Cut The Mustard :
Someone who isn't adequate enough to compete or participate.
Cast Iron Stomach:
Someone who has no problems, complications or ill effects with eating anything or drinking anything.
Stiffness in the leg / A leg cramp.
Chew someone out:
Verbally scold someone.
Chip on his Shoulder:
Angry today about something that occured in the past.
Close but no Cigar:
To be very near and almost accomplish a goal, but fall short.
Cock and Bull Story:
An unbelievable tale.
Come Hell Or High Water:
Any difficult situation or obstacle.
Crack Someone Up:
To make someone laugh.
Cross Your Fingers:
To hope that something happens the way you want it to.
Cry Over Spilt Milk:
When you complain about a loss from the past.
Intentionally raise a false alarm.
Cup Of Joe:
A cup of coffee.
Curiosity Killed The Cat:
Being Inquisitive can lead you into a dangerous situation.
Cut to the Chase:
Leave out all the unnecessary details and just get to the point.