methadone
Concise Oxford English Dictionary © 2008 Oxford University Press:
methadone /ˈmɛθədəʊn/
▶noun a powerful synthetic analgesic similar to morphine, used as a substitute drug in the treatment of heroin addiction.
– origin 1940s: from its chemical name, (6-di)meth(yl)a(mino-4,4-)d(iphenyl-3-heptan)one.
'methadone' also found in these Oxford entries:

