flying saucer vs unidentified flying object

flying saucer and unidentified flying object both are nouns.

Word	Noun	Adjective	Verb	Adverb
flying saucer	Yes	No	No	No
unidentified flying object	Yes	No	No	No

As nouns, flying saucer and unidentified flying object are synonyms defined as:

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

Other synonyms of flying saucer include UFO.

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