/ Thesaurus / R Synonyms of retardent Find synonyms for: Noun1. retardant, retardent, retardation, agentusage: any agent that retards or delays or hinders; "flame-retardant"WordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: heifer Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language