Xenonian is the native language spoken on the planet Xenon.
Background
It is primarily the language of the humans of Xenon.[1] It is apparently a dialect of the English language.[2]
Some exotic lonely Earthling men from Topeka, KA, are dying to meet Xenonian women.
Behind the scenes
Xenonian is occasionally used to describe stuff originating from Xenon, for example Xenonian television[3], or Xenonian women.[4] Not all 'Xenonians' are necessarily human... See the Green Girl. Xenonian is not a race but a description, and possibly 'citizenship' of its people humans, clones and alien races.
The people of Xenon are occasionally known as Xenonites.[5]
Xenonian (unofficial)
Fan ficton has occasionally used xenonian as a species/racial term for the people of Xenon.