An employee of a transport company, especially a pilot, traveling as a passenger for logistical reasons, for example to return home or travel to the next assignment.
Anyone traveling for free.
A train or truck moved between cities with no passengers or freight, in order to make it available for service.
A person staying at a lodging, such as a hotel or boarding house, without paying rent; freeloader.
A tree or tree branch fixed in the bottom of a river or other navigable body of water, partially submerged or rising nearly the surface, by which boats are sometimes pierced and sunk; snag.