/ Thesaurus / O Synonyms of once and for all Find synonyms for: Adverb1. conclusively, once and for allusage: in a conclusive way; "we settled the problem conclusively"WordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: diligent Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language