UFO 
/ˌju:ˌɛfˈoʊ/ noun
plural UFO's or UFOs /ˌju:ˌɛfˈoʊ/ noun /ˌju:ˌɛfˈoʊz/ [count] : a flying object in the sky that some people believe could be a spaceship from another planet
▪ a UFO sighting ◊UFO is as an abbreviation of “unidentified flying object.”
▪ a UFO sighting ◊UFO is as an abbreviation of “unidentified flying object.”
