adj. Originating from outside of the Earth's atmosphere, from space, or from another planet; alien to Earth or its environment.
n. A being originating from outside of the Earth's atmosphere, from space, or from another planet; an alien
the GNU version of the Collaborative International Dictionary of English
adj. originating or located or occurring outside Earth or its atmosphere.
n. a hypothetical form of life existing outside the Earth or its atmosphere, especially intelligent life on other planets or in other solar systems.
The Century Dictionary and Cyclopedia
Occurring outside of the earth; extramundane.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
n. a form of life assumed to exist outside the Earth or its atmosphere
adj. originating or located or occurring outside Earth or its atmosphere
Word Usage
"There, during the 60s and 70s, nearly all of the Apollo astronauts who walked on the moon were taught the basics in extraterrestrial exploration and earthworks."