Since the end of the Second World War, both laymen and scientists have given a great deal of thought to the possibility, or probability, of intelligent life elsewhere than on the earth - on other planets off the solar system, in other star systems of the Milky Way galaxy, and in other galaxies scattered through the physical universe. As a consequence, a large and varied vocabulary of terms designating different kinds of otherworldly beings has come into use.
Borgmann, Dmitri A.
"An Alien Lexicon,"
Word Ways: Vol. 18
, Article 7.
Available at: http://digitalcommons.butler.edu/wordways/vol18/iss1/7