Flying saucer
WordNet
noun
(1) An (apparently) flying object whose nature is unknown; especially those considered to have extraterrestrial origins
WiktionaryText
Noun
- An unidentified flying object; UFO; usually with disc-like properties.
- Some connect the recent spate of flying saucer sightings with a rumored top-secret military aviation project.
- In fiction, an alien interplanetary vessel with a disc-like shape and generally metallic appearance.