noun

1. a drug, as opium or any of its derivatives (morphine, heroin, codeine, etc.), used to relieve pain and induce sleep: narcotics are often addictive and in excessive doses can cause stupor, coma, or death
2. anything that has a soothing, lulling, or dulling effect

Etymology: ME narcotyke < OFr narcotique, orig. adj. < ML narcoticus < Gr narkoun, to benumb < narkē, numbness, stupor < IE *nerk- < base *(s)ner-, to twist, entwine > snare, narrow

adjective

1. of, like, or capable of producing narcosis
2. of, by, or for narcotic addicts