With all the current interest in space travel, rocketry, and so on, ultramundane is a word that should become ever more important, although, being polysyllabic, it may never become part of the argot of the “man in the street.”
For, with the literal meaning of “out of this world,” it can well apply to the various aspects of the exploration of outer space.
As the appearance of the word would indicate, it is of Latin origin, coming from the Late Latin ultramundanus, from ultra, “beyond,” and mundus, “the world.”