Breadcrumb Home > Thesaurus > M Synonyms of methadone Find synonyms for: Noun1. methadone, methadone hydrochloride, methadon, dolophine hydrochloride, fixer, synthetic heroin, narcoticusage: synthetic narcotic drug similar to morphine but less habit-forming; used in narcotic detoxification and maintenance of heroin addictionWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved.Definition and meaning of methadone (Dictionary) ✖ Related Content Daily Word Quiz: hieratic Analogy of the Day: Today’s Analogy Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language