UFO /ˈjuːfəʊ, ˌjuː ef ˈəʊ $ -foʊ, -ˈoʊ/ noun [countable]
(unidentified flying object) a strange object in the sky, that some people believe is a spaceship from another world Synonym : flying saucer

[TahlilGaran] Dictionary of Contemporary English ▲

UFO
Unidentified Flying Object
The number of UFO sightings has increased dramatically recently.

[TahlilGaran] English Idioms Dictionary ▲

u.f.o.
n. phr. Unidentified Flying Object.
Some people think that the U.F.O.s are extraterrestrial beings of higher than human development who pay periodic visits to Earth to warn us of our self-destructive tendencies.

[TahlilGaran] English Idioms Dictionary ▲

UFO
Unidentified Floating Object 
Unidentified Flying Object

[TahlilGaran] Acronyms and Abbreviations Dictionary ▲