/ Thesaurus / R Synonyms of ruthlessness Find synonyms for: Noun1. pitilessness, ruthlessness, mercilessness, unmercifulnessusage: mercilessness characterized by a lack of pity2. cruelty, mercilessness, pitilessness, ruthlessness, heartlessness, coldheartedness, hardheartednessusage: feelings of extreme heartlessnessWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: beseech Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language