>"A tramp is a migratory worker. A hobo is a migratory non-worker. A bum is >a non-migratory non-worker" is the way I heard it. This is largely correct as I understand the terms, except that in the idealized version hoboes will do odd or temporary jobs for money or food. They are "knights of the road" who work in order to travel, while tramps travel in order to work.