her·​o·​in | \ˈher-ə-wən, ˈhe-rə-\

Definition of heroin 

: 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

Keep scrolling for more

Other Words from heroin

heroinism \ˈher-​ə-​wə-​ˌni-​zəm, ˈhe-​rə-​ \ noun

Examples of heroin in a Sentence

Recent Examples on the Web

Obama has come with grim news: Biden’s favorite Amtrak conductor, Finn Donnelly, had been found dead on the train tracks outside of Wilmington station, with a bag of heroin in his pocket. Alexandra Alter, New York Times, "The Obama-Biden Bromance Continues. This Time in a Mystery Novel.," 12 July 2018 The 17½ pounds of heroin has a street value of $400,000, according to a Cobb sheriff’s office news release. Ben Brasch, ajc, "Cops: Cobb parents had $400K of heroin in home with 2-year-old girl," 6 July 2018 In Guerrero — a hub for cultivation of the opium poppy, the raw material in the production of heroin — 10 candidates for local posts in the rural town of Cutzamala de Pinzon, home to about 5,000 people, have withdrawn from the race. Patrick J. Mcdonnell, latimes.com, "Slayings of political candidates accelerate in run-up to Mexico election," 27 June 2018 In July 2017, The Enquirer embarked on a week-long reporting project to tell the story of heroin in our community. Sallee Ann Ruibal, Cincinnati.com, "3 headlines you may have missed: Pulitzer plans, hitting the green and spring break plans," 26 June 2018 Kelly Cochran later injected her husband with a lethal dose of heroin in February 2016. Caroline Blackmon, Detroit Free Press, "Michigan woman may have served ex-lover's remains at U.P. barbecue," 20 June 2018 Denise Hanna has never forgotten that the driver who killed her son nearly six and a half years ago was under the influence of heroin. Staff Report, The Aegis, "Harford ramps up summer campaign to prevent opioid abuse, provide treatment," 15 June 2018 Robinson is the only defendant accused of distribution of heroin. Marie Simoneaux, NOLA.com, "Former Orleans coroner's employee sold heroin from morgue van: court documents," 5 June 2018 Brian Chambers, 29, and Kevin Barlow, 28, were hanged in 1986 after being found with nearly 180 grams of heroin. Eli Meixler, Time, "An Australian Grandmother Has Been Sentenced to Death for Drug Smuggling in Malaysia," 26 May 2018

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.

See More

First Known Use of heroin

1898, in the meaning defined above

History and Etymology for heroin

from Heroin, a trademark

Keep scrolling for more

Learn More about heroin

Statistics for heroin

Last Updated

4 Dec 2018

Look-up Popularity

Time Traveler for heroin

The first known use of heroin was in 1898

See more words from the same year

Keep scrolling for more

More Definitions for heroin



English Language Learners Definition of heroin

: a powerful illegal drug that is made from morphine


her·​o·​in | \ˈher-ə-wən \

Kids Definition of heroin

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


her·​o·​in | \ˈher-ə-wən \

Medical Definition of heroin 

: 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

Keep scrolling for more

More from Merriam-Webster on heroin

Spanish Central: Translation of heroin

Nglish: Translation of heroin for Spanish Speakers

Britannica English: Translation of heroin for Arabic Speakers

Britannica.com: Encyclopedia article about heroin

Comments on heroin

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


a soft lustrous wool fabric with mohair

Get Word of the Day daily email!

Test Your Vocabulary

Late Autumn 2018 Words of the Day Quiz

  • frosted-autumn-leaves
  • Which is a synonym of yahoo?
How Strong Is Your Vocabulary?

Test your vocabulary with our 10-question quiz!


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


Love words? Need even more definitions?

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