What is the meaning of Deadhead?

A person either admitted to a theatrical or musical performance without charge, or paid to attend.

An employee of a transport company, especially a pilot or flight attendant, 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 stupid or boring person; dullard.

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.

Driftwood.

Alternative form of Deadhead (fan of the rock band The Grateful Dead)

A zombie.

To admit to a performance without charge.

To travel as a deadhead, or non-paying passenger.

To drive an empty vehicle.

To send (a person or message) for free.

To remove spent or dead blossoms from a plant.

Source: wiktionary.org