ex·​tra·​ter·​res·​tri·​al | \ ˌek-strə-tə-ˈre-strē-əl How to pronounce extraterrestrial (audio) , -ˈres-chəl, -ˈresh-chəl \

Definition of extraterrestrial

 (Entry 1 of 2)

: originating, existing, or occurring outside the earth or its atmosphere extraterrestrial life



Definition of extraterrestrial (Entry 2 of 2)

: a being from another world : an extraterrestrial being

Examples of extraterrestrial in a Sentence

Recent Examples on the Web: Adjective Since many planets are icebound or experience extreme temperatures, digging down into frozen areas might enable scientists to eventually find extraterrestrial life. David Kindy, Smithsonian Magazine, 23 July 2021 Do the unidentified aerial phenomena affirm extraterrestrial life? Ella Lee, USA TODAY, 25 June 2021 If their findings support the new picture, Mars, the longtime hope for discovering signs of ancient extraterrestrial life, will have a rival. Paul Voosen, Science | AAAS, 9 June 2021 The report didn’t mention the fringe belief that UFOs are spacecraft flown by extraterrestrial beings, a theory popular among enthusiasts but totally lacking in evidence. Joe Walsh, Forbes, 25 June 2021 What happened in 1994 remains a mystery, much like everything else related to the possibility of extraterrestrial life. Emma Stein, Detroit Free Press, 1 July 2021 But there’s a big difference between believing in extraterrestrial life (which seems almost a certainty, according to astrobiologists), and believing that said extraterrestrials regularly come and visit us. Dani Di Placido, Forbes, 28 June 2021 Investigators found no evidence that the sightings represented either extraterrestrial life or a major technological advancement by a foreign adversary like Russia or China. Veronica Rocha, CNN, 25 June 2021 At a recent forum about my popular-level book Extraterrestrial and new textbook Life in the Cosmos, I was asked how long humans could ignore extraterrestrial intelligent life. Avi Loeb, Scientific American, 24 June 2021 Recent Examples on the Web: Noun The town celebrates its connection to the extraterrestrial with a UFO Days festival the last weekend in July. Chelsey Lewis, Milwaukee Journal Sentinel, 30 June 2021 Sincere believers in the extraterrestrial are framed as kooky punchlines across news, TV and film. Laura Blasey, Los Angeles Times, 2 June 2021 Doja Cat paid homage to sci-fi classics including Signs, Poltergeist and the X-Files during her extraterrestrial (and extra delightful) performance at the 2021 iHeartRadio Music Awards. Katie Bain, Billboard, 27 May 2021 As to the object’s origin, speculation ranged from the extraterrestrial to someone’s attempt at art. Sunset Magazine, 25 Nov. 2020 The most striking images were from San Francisco proper, which was bathed in a zestless citrus haze, as if some evil extraterrestrial had zapped Karl the Fog with a deadly malady. Steven Levy, Wired, 11 Sep. 2020 Below his sweet words to his wife, Taylor, there’s a pair of the cartoonist’s trademark blue extraterrestrials. Byangela Haupt, Washington Post, 11 Feb. 2020 Another thing that enterprising extraterrestrials might do is simply monitor the total amount of light coming from Earth — even seen in a single pixel. NBC News, 18 Sep. 2019 Sharon Wehrly, the sheriff in adjacent Nye County, home to the Area 51 Alien Center, said messages discouraging Earthlings from trying to find extraterrestrials in Amargosa Valley appeared to work. Travis Fedschun, Fox News, 20 Sep. 2019

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'extraterrestrial.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of extraterrestrial


1848, in the meaning defined above


1950, in the meaning defined above

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The first known use of extraterrestrial was in 1848

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Last Updated

30 Jul 2021

Cite this Entry

“Extraterrestrial.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/extraterrestrial. Accessed 30 Jul. 2021.

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More Definitions for extraterrestrial



English Language Learners Definition of extraterrestrial

: coming from or existing outside the planet Earth

More from Merriam-Webster on extraterrestrial

Nglish: Translation of extraterrestrial for Spanish Speakers


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