Breadcrumb Home > Thesaurus > M Synonyms of mantissa Find synonyms for: Noun 1. mantissa, fixed-point part, fraction usage: the positive fractional part of the representation of a logarithm; in the expression log 643 = 2.808 the mantissa is .808 WordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved.Definition and meaning of mantissa (Dictionary) TrendingHere are the facts and trivia that people are buzzing about. Jewish Holidays, 2010-2030 (A.M. 5770-5791) Western Christian Holidays, 2010-2030 12 Steps to a New Year New Year's Resolution to Slim Down? Martin Luther King Speeches Books of the Bible: Old Testament Books in Order ✖ Related Content Daily Word Quiz: derogate Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language