/ Thesaurus / S Synonyms of sine qua non Find synonyms for: Noun1. essential condition, sine qua non, prerequisite, requirementusage: a prerequisiteWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: acerbity Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language