Breadcrumb Home > Thesaurus > U Synonyms of ufo Find synonyms for: Noun 1. unidentified flying object, UFO, flying saucer, apparition, phantom, phantasm, phantasma, fantasm, shadow usage: an (apparently) flying object whose nature is unknown; especially those considered to have extraterrestrial origins WordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved.Definition and meaning of ufo (Dictionary) TrendingHere are the facts and trivia that people are buzzing about. Chinese New Year History, Meaning, and Celebrations Current Events This Week: February 2024 Valentine's Day Valentine's Day History Mardi Gras 30 "Charlie and the Chocolate Factory" Quotes ✖ Related Content Daily Word Quiz: spelunk Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language