heroin Definition

heroin
noun

1. A powerful drug produced from morphine, used medicinally to lessen pain, and illegally for pleasure, but with continued use likely to lead to dependence and addiction. Technical equivalent diamorphine.

Etymology: 19c: from German Heroin, from Greek heros hero, perhaps from the initial feeling of euphoria produced.

Info:

There is sometimes a spelling confusion between heroin and heroine.