Definitions of narcotic:

• noun:   a drug that produces numbness or stupor; often taken for pleasure or to reduce pain; extensive use can lead to addiction
• adjective:   inducing mental lethargy

  Example: "A narcotic speech"

• adjective:   inducing stupor or narcosis

  Example: "Narcotic drugs"

• adjective:   of or relating to or designating narcotics

  Example: "Narcotic addicts"