Have you ever considered working per diem? Many medical professionals work per diem to pick up some extra money in addition to their full-time positions, but others choose to only work per diem shifts without having a full-time job. Per diem is a Latin term meaning per day or each day, as in daily.. In medical careers, per diem refers to very short-term temporary employment that consists of just a few days of employment to fill in for a sick or vacationing full-time clinician.