1. (narrow-sense) An opiate, such as heroin, morphine, codeine, etc.
2. (broad-sense) A powerful mind-altering substance, usually illegal (tho not necessarily, see DXM, an over-the-counter narcotic, and hillbilly heroin, Ritalin, Vicodin, etc. which are legally prescribed).
1. Opiates are classic narcotics.
2. <Drug Warrior> Look at all those newfangled narcotics going around! The country's goin' to hell in a handbasket.