unidentified flying object

Definition of Unidentified Flying Object in English :

1. flying saucer, ufo, unidentified flying object

an (apparently) flying object whose nature is unknown; especially those considered to have extraterrestrial origins

WordNet Lexical Database for English. Princeton University. 2010.

Unidentified Flying Object

noun

an object seen in the sky or landing on earth which cannot be identified and which is often believed to be from another planet

The police were flooded with calls about unidentified flying objects.

n.

1. A flying or apparently flying object of an unknown nature, especially one suspected to have been sent by extraterrestrial beings.

2. A flying saucer.