extraterrestrial

American  

[ek-struh-tuh-res-tree-uhl] / ˌɛk strə təˈrɛs tri əl /

adjective

1. 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.

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noun

1. a being originating from beyond the earth; an alien from outer space.

   It was your typical sci-fi novel about extraterrestrials conquering the earth.

extraterrestrial British  

/ ˌɛkstrətɪˈrɛstrɪəl /

adjective

1. occurring or existing beyond the earth's atmosphere

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noun

1. (in science fiction) a being from beyond the earth's atmosphere

extraterrestrial Scientific  

/ ĕk′strə-tə-rĕs′trē-əl /

1. Originating, located, or occurring outside the Earth or its atmosphere.

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extraterrestrial Cultural  

1. A descriptive term for things outside the Earth, such as possible civilizations outside the solar system, or objects, such as meteorites, that actually reach the Earth.

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Other Word Forms

• extraterrestrially adverb

Etymology

Origin of extraterrestrial

First recorded in 1865–70; extra- + terrestrial

Example Sentences

That kind of global spending sounds good but what about extraterrestrial spending?

From Barron's • Mar. 30, 2026

“We’re gonna have superstars, superheroes, and there is also going to be an extraterrestrial on the stage, so you can figure that one out,” Mullan said.

From Los Angeles Times • Mar. 11, 2026

US President Donald Trump says he will direct US agencies, including the defence department, to "begin the process of identifying and releasing" government files on aliens and extraterrestrial life.

From BBC • Feb. 19, 2026

This shift in thinking could expand how scientists search for extraterrestrial life.

From Science Daily • Feb. 11, 2026

If we should receive a radio message from an extraterrestrial civilization, how could it possibly be understood?

From "Cosmos" by Carl Sagan