English Reference
noun

heroin

n.
US /ˈhɛɹoʊən/ UK /hˈɛɹəʊˌɪn/ hero·in UK spelling heroins

  1. 01 B2 Upper Intermediate Technical Medicine

    a powerful and illegal drug made from opium that people often inject or smoke.

    a potent, highly addictive semi-synthetic opioid derived from morphine; it is classified as a Schedule I narcotic in many jurisdictions.

    Simple

    The police arrested the man for selling heroin near the park.

    In context

    Public health officials are implementing new harm-reduction strategies to combat the rising number of heroin overdoses in urban areas.

    Usage

    Uncountable when referring to the substance in general; countable only in specific forensic or chemical contexts.

    Teacher's tip

    Learners frequently confuse the spelling of this drug with 'heroine' (a female hero). Note that the drug never has an 'e' at the end.

    Pitfall
    The story's heroin was very brave. The story's heroine was very brave.

    Do not confuse 'heroin' (the drug) with 'heroine' (a female hero). They sound the same but have different spellings and meanings.

Drugs such as heroin were seen as dangerous and bad, so they were banned.

The Conversation· 9 Sept 2026

Cravings ‘like heroin withdrawal’: what happens when weight-loss drugs don’t work?

The Guardian· 7 Sept 2026
This entry
Level C1 · Advanced
Frequency Frequent
Updated