Wordnet 3.0
NOUN (1)
1. 
 synthetic narcotic drug similar to morphine but less habit-forming; 
 used in narcotic detoxification and maintenance of heroin addiction; 
[syn: methadone, methadone hydrochloride, methadon, dolophine hydrochloride, fixer, synthetic heroin]
WordNet (r) 3.0 (2006):
synthetic heroin
    n 1: synthetic narcotic drug similar to morphine but less habit-
         forming; used in narcotic detoxification and maintenance of
         heroin addiction [syn: methadone, methadone
         hydrochloride, methadon, dolophine hydrochloride,
         fixer, synthetic heroin]