"of or pertaining to the planet Earth," 1881, in science fiction writing, from Latin terra (see terrain). Also used as a noun meaning "inhabitant of the Earth" (1953). An earlier form, terrene was used in Middle English in sense of "belonging to this world, earthly, secular, temporal" (c.1300), later, "of the Earth as a planet" (1630s).
Examples from the Web for terran
When a geek prince hired out as a laborer for a year on Niflheim, he did so for only one purpose—to learn Terran technologies.Uller Uprising|Henry Beam Piper, John D. Clark and John F. Carr
And the Terran began to realize that his present search might well be fruitless, though he fought against accepting it.
Thirty minutes--twenty-six and a fraction of the Terran minutes he had become accustomed to--until he'd have to face it.Graveyard of Dreams|Henry Beam Piper
The Terran was on his feet and headed back, intent on returning to the sea cave and starting out after Ashe as soon as he could.
The Terran raised the bowl to that spot of light which marked Tyr's pale sun.Storm Over Warlock|Andre Norton