Breadcrumb Home > Thesaurus > I Synonyms of imbecility Find synonyms for: Noun 1. imbecility, retardation, mental retardation, backwardness, slowness, subnormality usage: retardation more severe than a moron but not as severe as an idiot 2. stupidity, betise, folly, foolishness, imbecility, mistake, error, fault usage: a stupid mistake WordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved.Definition and meaning of imbecility (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: cognoscenti Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language