UFO

noun

ˌyü-(ˌ)ef-ˈō 

ˈyü-(ˌ)fō

plural UFO's or UFOs ˌyü-(ˌ)ef-ˈōz 

ˈyü-(ˌ)fōz

: a mysterious flying object in the sky that is sometimes assumed to be a spaceship from another planet : unidentified flying object

"All right." The President sighed. "Is there anybody around this table who thinks UFOs and this signal from Vega have anything to do with each other?"

—Carl Sagan

In 1966, the first UFO "abduction" was described in journalist John G. Fuller's book The Interrupted Journey.

—Keay Davidson

called also UAP, unidentified aerial phenomenon, unidentified anomalous phenomenon

Examples of UFO in a Sentence

Recent Examples on the Web

Prior to the series launch, Manga Productions also released the game UFO Robot Grendizer: The Feast of the Wolves in MENA in cooperation with the French company Microids. —Melanie Goodfellow, Deadline, 11 June 2025

Featuring kicky period tunes and fantastic production design, the film stars Jason Schwartzman, Scarlett Johansson and others as parents of talented kids who gather for a science convention and are quarantined by the government when a UFO shows up. —Brian Truitt, USA Today, 5 June 2025

Trump vows greater transparency President Donald Trump has famously been a UFO skeptic. —Devin Dwyer, ABC News, 4 June 2025

Over the course of Steven Spielberg's movie, UFO sightings, toys coming to life, and visions of Devils Tower in Wyoming (subsequently recreated in mashed potato) gradually evolve into something more spectacular. —Richard Edwards, Space.com, 3 June 2025

Word History

Etymology

unidentified flying object

First Known Use

1953, in the meaning defined above

Rhymes for UFO

• acknow
• aglow
• ago
• airglow
• aloe
• altho
• although
• ammo
• backflow
• backhoe
• banjo
• barbeau

Kids Definition

UFO

noun

ˌyü-(ˌ)ef-ˈō 

plural UFO's or UFOs -ˈōz 

: an unidentified flying object

especially : flying saucer