Breadcrumb Home > Thesaurus > F Synonyms of fission Find synonyms for: Noun 1. fission, asexual reproduction, agamogenesis usage: reproduction of some unicellular organisms by division of the cell into two more or less equal parts 2. fission, nuclear fission, nuclear reaction usage: a nuclear reaction in which a massive nucleus splits into smaller nuclei with the simultaneous release of energy WordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved.Definition and meaning of fission (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: eponymous Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language