ufo

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

flying saucer unidentified flying object

Ufa

U.K. UK UN up Ur U.S. US ut UV ux.

Uca UDA Ufa UHF uke Ull ult Uma ump Unq Urd URL urn USA U.S.A. use USN Uta UTC Ute UTN Utu Uub Uuh Uup Uuq Uut Uzi