UFO

American  

[yoo-ef-oh, yoo-foh] / ˈjuˈɛfˈoʊ, ˈju foʊ /

abbreviation

UFO's, plural UFOs plural

1. unidentified flying object: any unexplained moving object observed in the sky, especially one assumed by some observers to be of extraterrestrial origin.

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UFO British  

/ ˈjuːfəʊ /

abbreviation

1. unidentified flying object

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UFO ¹ Cultural  

1. The abbreviation for u nidentified f lying o bject. Sometimes referred to colloquially as “flying saucers.” Most UFO sightings have prosaic explanations; there is no hard evidence that extraterrestrial beings are visiting Earth.

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UFO ² Cultural  

1. An abbreviation for “U nidentified F lying O bject.” Often described as “flying saucers,” some UFOs are believed to come from other planets or galaxies and thus support the idea that human beings are not the only form of intelligent life in the universe. Few scientists agree.

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Usage

See UAP.

Etymology

Origin of UFO

First recorded 1950–55

Example Sentences

In 2020, on the Tyler Cowen podcast, Obama CIA chief John Brennan responded to UFO sightings over U.S. military training ranges by clearly suggesting alien life.

From The Wall Street Journal • Jun. 26, 2026

He said that “most of the space-focused ETFs in the market are down further than UFO over the past month, because they are concentrated around a smaller number of more volatile space stocks.”

From MarketWatch • Jun. 24, 2026

Meanwhile, earlier this spring, the U.S. government declassified another batch of UFO files and the response was roughly equivalent to a collective shrug.

From Los Angeles Times • Jun. 11, 2026

A particularly intriguing chapter in Hill's back story is her link to one of the most famous episodes in UFO folklore.

From Barron's • May 29, 2026

They stared at me like I was Bigfoot or a UFO.

From "The Absolutely True Diary of a Part-Time Indian" by Sherman Alexie