Shut up and squat. A variation on the famed 'Keep clam!' of Ivor's Acres of Clams in Seattle, Washington. Problem is, it sounds like a back-formation for 'clam up', which it is not, sort of.
You didn't lose your billfold. Look through the car. You'll find it. Just shut up and clam down.
by Byron Black September 30, 2007