Earthling is an alternate term to refer to a member of the Human race, particularly one born on their homeworld, Earth. It was apparently the favored term during the Ur-Quan Slave War. In all other contexts, including most Hierarchy communications of the Star Control II era, "Human" remained the most common term.
Earthling has passed out of popular usage, except in the official designation for the Human combat vessel: the Earthling Cruiser.
See Also: Human