Merriam-Webster Collegiate Dictionary - narcotic

 I. noun  Etymology: Middle English narkotik, from Middle French narcotique, from narcotique, adjective, from Medieval Latin ~us, from Greek narkotikos, from narkoun to benumb, from narke numbness — more at snare  Date: 14th century  1.  a. a drug (as opium or morphine) that in moderate doses dulls the senses, relieves pain, and induces profound sleep but in excessive doses causes stupor, coma, or convulsions  b. a drug (as marijuana or LSD) subject to restriction similar to that of addictive ~s whether physiologically addictive and ~ or not  2. something that soothes, relieves, or lulls  II. adjective  Date: 1526  1.  a. having the properties of or yielding a ~  b. inducing mental lethargy  2. of, induced by, or concerned with ~s  3. of, involving, or intended for ~ addicts  • ~ally adverb