UFO

play
noun \ˌyü-(ˌ)ef-ˈō\

Definition of UFO

plural

UFO's

or

UFOs

play \-ˈōz\
  1. :  an unidentified flying object; especially :  flying saucer

Origin and Etymology of ufo

unidentified flying object


First Known Use: 1953


UFO Defined for English Language Learners

UFO

play
noun \ˌyü-(ˌ)ef-ˈō\

Definition of UFO for English Language Learners

  • : a flying object in the sky that some people believe could be a spaceship from another planet


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