There are many terms from classic and modern SF that remain unresearched, and the Historical Dictionary of Science Fiction will be continually updated, especially as additional resources are put online. Boing Boing is syndicating new entries from the HDSF on a regular basis. (Read the series introduction.)
Terrene
There are many demonyms in SF that refer to natives or inhabitants of Earth, including Earthian, Earther, earthling, Tellurian, and Terrestrial. A favorite of ours is Terran, which derives from Terra, from the Latin word terra 'earth'; it just sounds like a good word for the concept: foreign enough that it feels like a genuine proper name, not so foreign that you have to stop to puzzle it out.
Terran dates from the mid-1930s; we are now adding an earlier variant, Terrene (along with its related (and more common) adjective Terrene), which are slightly earlier, from the late 1920s. In English, the -ene suffix (ultimately deriving from Greek) is used to form names of natives or inhabitants of particular places, especially in Asia Minor, such as Damascene or Nazarene; here it is applied to Terra as a name for Earth itself.
While we're here, we're also extending Earthian by adding the rare spelling variant Earthean (and its adjective).
