Meaning

noun a narcotic that is considered a hard drug; a highly addictive morphine derivative; intravenous injection provides the fastest and most intense rush

originSince the 1890s, from German Heroin, originally a trademark, from Ancient Greek ἥρως (hḗrōs, “hero”) and the suffix -in (“-ine”). Said to have been called thus to evoke quick and sweeping effect as a painkiller and cough suppressant (its original uses). Alternatively explained as a reference to the heroic school of medicine.

Etymology from Wiktionary, CC BY-SA 3.0