Latin meaning per day. The payment of an amount to cover a specific task or job for an employee or consultant. In some companies this is a set maximum amount of reimbursement that a company will provide the employee for travel. Per Diem is a term most commonly used by lawyers to describe the hiring of an attorney for the sole purpose of making required appearances in court that are routine in nature and are handled by temporary attorneys who are paid a set rate for their appearance.
PER DIEM
TheLaw.com Law Dictionary & Black's Law Dictionary 2nd Ed.