- outside, or originating outside, the limits of the earth: People on earth have long speculated about the idea of extraterrestrial life.Cataclysmic wildfires could be expected if earth were to take an extraterrestrial hit.
- a being originating from beyond the earth; an alien from outer space: It was your typical sci-fi novel about extraterrestrials conquering the earth.
- occurring or existing beyond the earth's atmosphere
- (in science fiction) a being from beyond the earth's atmosphere
