Breadcrumb Home > Thesaurus > O Synonyms of once Find synonyms for: Adverb 1. once, one time, in one case usage: on one occasion; "once I ran into her" 2. once usage: as soon as; "once we are home, we can rest" 3. once, formerly, at one time, erstwhile, erst usage: at a previous time; "at one time he loved her"; "her erstwhile writing"; "she was a dancer once"; WordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved.Definition and meaning of once (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: vacuous Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language