Breadcrumb Home > Thesaurus > R Synonyms of rubicon Find synonyms for: Noun 1. Rubicon usage: the boundary in ancient times between Italy and Gaul; Caesar's crossing it with his army in 49 BC was an act of war 2. Rubicon, point of no return, line, dividing line, demarcation, contrast usage: a line that when crossed permits of no return and typically results in irrevocable commitment WordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved.Definition and meaning of rubicon (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: inmediasres Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language