PEBKAC /pebkak/ [Abbrev., Problem Exists Between Keyboard And Chair ] Used by support people, particularly at call centers and help desks. Not used with the public. Denotes pilot error as the cause of the crash, especially stupid errors that even a luser could figure out. Very derogatory. Usage: Did you ever figure out why that guy couldn't print? Yeah, he kept cancelling the operation before it could finish. PEBKAC. See also ID10T. Compare pilot error , UBD.