narcotic
Concise Oxford English Dictionary © 2008 Oxford University Press:
narcotic/nɑːˈkɒtɪk/
▶noun an addictive drug, especially an illegal one, that affects mood or behaviour.
■ Medicine a drug which induces drowsiness, stupor, or insensibility and relieves pain.
▶adjective relating to narcotics.– derivatives
narcotically adverb,
narcotism noun
narcotize (or narcotise) verb.
narcotically adverb,
narcotism noun
narcotize (or narcotise) verb.
– origin ME: from OFr. narcotique, via med. L. from Gk narkōtikos, from narkoun ‘make numb’.
'narcotic' also found in these Oxford entries:

