/ Thesaurus / R Synonyms of relentlessly Find synonyms for: Adverb1. relentlessly, unrelentinglyusage: in a relentless manner; "he worked relentlessly"WordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: cautious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language