heroin

play
noun her·o·in \ˈher-ə-wən, ˈhe-rə-\

Definition of heroin

  1. :  a strongly physiologically addictive narcotic C21H23NO5 that is made by acetylation of but is more potent than morphine and that is prohibited for medical use in the U.S. but is used illicitly for its euphoric effects

heroinism

play \ˈher-ə-wə-ˌni-zəm, ˈhe-rə-\ noun

Recent Examples of heroin from the Web

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'heroin'. Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Origin and Etymology of heroin

from Heroin, a trademark


HEROIN Defined for English Language Learners

heroin

play
noun

Definition of heroin for English Language Learners

  • : a powerful illegal drug that is made from morphine


HEROIN Defined for Kids

heroin

play
noun her·o·in \ˈher-ə-wən\

Definition of heroin for Students

  1. :  a very harmful illegal drug that is highly addictive and is made from morphine


Medical Dictionary

heroin

play
noun her·o·in \ˈher-ə-wən\

Medical Definition of heroin

  1. :  a strongly physiologically addictive narcotic C21H23NO5 that is made by acetylation of but is more potent than morphine and that is prohibited for medical use in the United States but is used illicitly for its euphoric effects—called also acetomorphine, diacetylmorphine, diamorphine



Seen and Heard

What made you want to look up heroin? Please tell us where you read or heard it (including the quote, if possible).

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

WORD OF THE DAY

marked by lack of plan or order

Get Word of the Day daily email!

Test Your Vocabulary

The Emoji Quiz

  • emoji-the-quiz
  • What phase of the moon is this: 🌖 ?
Spell It

Can you spell these 10 commonly misspelled words?

TAKE THE QUIZ
Dictionary Devil

Test Your Knowledge - and learn some interesting things along the way.

TAKE THE QUIZ

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!