The High Debraman and Chairman of the Yokuta Elders is a position as well as a name. The Yokuta in leading roles traditionally take on the title associated with a post as new name.
A Debraman is best translated as Foreman or Team leader. The High Debraman of the Yokuta Elders is the defacto leader of his society.
He can be overruled by the other elders, but that rarely if ever happens.
(Galactic Chronicles 6: First Journeys)