Predor was the title of a Rakatan overlord. Skal'nas and Tul'kar were Predors in the Infinite Empire. However, one Predor could be overlord to another Predor, as Skal'nas was superior in rank to Tul'kar. Despite this, Skal'nas could not commandeer Tul'kar's Force Hound without meeting him in combat.
The Over-Predor ruled the Infinite Empire.
The title of Predor sounds similar to the Latin word prætor, which originally designated a magistrate with the ability to lead armies.