unidentified anomalous phenomenon

noun

plural unidentified anomalous phenomena

: a mysterious phenomenon (especially an unidentified aerial phenomenon) that is sometimes assumed to be a spaceship from another planet : uap

—used especially as an alternative to UFO or unidentified flying object

Unidentified anomalous phenomena, or UAP, "are events in the sky that cannot be identified as aircraft or known natural phenomena from a scientific perspective," according to NASA. The term UAP, originally meaning unidentified aerial phenomena, was changed by the National Defense Authorization Act, which was signed into law in December, [Dan] Evans said. The change occurred in recognition of the fact that the search for UAP should include near space and undersea phenomena as well, he said.

—Ashley Strickland

The director of the Pentagon's new UFO office shot down hopes that the buzz over unidentified anomalous phenomena (UAP) supports claims of extraterrestrial visitation.

—Brett Tingley

Examples of unidentified anomalous phenomenon in a Sentence

Recent Examples on the Web

The site, which contains newly declassified government documents on unidentified anomalous phenomena (UAP) — the more modern term for what were traditionally called UFOs — launched on Friday morning, May 8. —Toria Sheffield, PEOPLE, 10 May 2026

The Pentagon is starting to release files related to unidentified anomalous phenomena (UAP), or unidentified flying objects (UFOs). —Adam Kovac, Scientific American, 8 May 2026

The documents form part of a broader federal effort to release records related to unidentified anomalous phenomena. —Sarah Rumpf-Whitten, FOXNews.com, 8 May 2026

UFOs, the term for unidentified flying objects, has in recent years given way to UAP — unidentified aerial phenomena or unidentified anomalous phenomena. —ABC News, 4 Apr. 2026

But in the case of flying saucers and unidentified anomalous phenomena, what's truly going on seems elusive. —Leonard David, Space.com, 4 Apr. 2026

Sleeping Dog has been decades in the making and chronicles Corbell’s unlikely path from mixed martial artist to a journalist at the center of the battle for disclosure of unidentified anomalous phenomena. —Ryan Gajewski, HollywoodReporter, 27 Mar. 2026

The surge of public interest is the latest chapter in a decades-long fascination with unidentified anomalous phenomena, or UAPs, the modern term for UFOs. —Danya Gainor, CNN Money, 7 Mar. 2026

Bianco was part of NASA's independent team studying unidentified anomalous phenomena. —Graham Kates, CBS News, 24 Feb. 2026

Word History

First Known Use

2020, in the meaning defined above

Rhymes for unidentified anomalous phenomenon

• agamemnon
• automaton
• diencephalon
• panopticon
• aileron
• antiphon
• autobahn
• carillon
• castellan
• celadon
• cephalon
• cynodon