Breadcrumb Home > Thesaurus > O Synonyms of or Find synonyms for: Noun 1. Oregon, Beaver State, OR usage: a state in northwestern United States on the Pacific 2. operating room, OR, operating theater, operating theatre, surgery, hospital room usage: a room in a hospital equipped for the performance of surgical operations; "great care is taken to keep the operating rooms aseptic" WordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved.Definition and meaning of or (Dictionary) TrendingHere are the facts and trivia that people are buzzing about. Hanukkah Origins of the Christmas Holiday Jewish Holidays, 2010-2030 (A.M. 5770-5791) Western Christian Holidays, 2010-2030 Krampus: The Christmas Devil Kwanzaa ✖ Related Content Daily Word Quiz: tintinnabulation Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language