fentanyl

noun

fen·​ta·​nyl ˈfen-tə-ˌnil How to pronounce fentanyl (audio)
: a synthetic opioid narcotic analgesic C22H28N2O with pharmacological action similar to morphine that is administered transdermally as a skin patch and in the form of its citrate C22H28N2O·C6H8O7 is administered orally or parenterally (as by intravenous or epidural injection)

Examples of fentanyl in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
The trafficking ring allegedly distributed meth, fentanyl, cocaine and other drugs. — Kansas City Star, 25 June 2026 Both were federally charged with conspiracy to possess with intent to distribute heroin and fentanyl. — Robert McGreevy, FOXNews.com, 3 July 2026 The suit did not specify what drug was involved, but said responding officers and paramedics gave the teen who sued multiple doses of Narcan, which is used to reverse overdoses caused by opioids such as fentanyl. — James Queally, Los Angeles Times, 30 June 2026 On March 24, Acosta-Reyes pleaded guilty to conspiracy to distribute and to possess with intent to distribute 400 grams or more of fentanyl, court records show. — Staff Report, Hartford Courant, 27 June 2026 See All Example Sentences for fentanyl

Word History

Etymology

probably alteration of phenethyl, a monovalent radical derived from ethylbenzine, from phen- + ethyl

First Known Use

1964, in the meaning defined above

Time Traveler
The first known use of fentanyl was in 1964

Rhymes for fentanyl

See All Rhymes for fentanyl

Browse Nearby Words

fent
fentanyl
fenthion
See all Nearby Words

Cite this Entry

“Fentanyl.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/fentanyl. Accessed 7 Jul. 2026.

Copy Citation

Medical Definition

fentanyl

noun
fen·​ta·​nyl ˈfent-ᵊn-ˌil How to pronounce fentanyl (audio)
: a synthetic opioid narcotic analgesic C22H28N2O with pharmacological action similar to morphine that is administered transdermally as a skin patch and in the form of its citrate C22H28N2O·C6H8O7 is administered orally or parenterally

Note: Fentanyl is marketed under the trademark Actiq.

More from Merriam-Webster on fentanyl

Britannica.com: Encyclopedia article about fentanyl

Last Updated: - Updated example sentences
Love words? Need even more definitions?

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

Popular in Grammar & Usage

See More

Is that lie 'bald-faced' or 'bold-faced'?

'A' or 'an'? What about before 'h'? An Indefinite Article Guide

Why is '-ed' sometimes pronounced at the end of a word?

Commonly Misspelled Words

How to Use Em Dashes (—), En Dashes (–) , and Hyphens (-)
See More

Popular in Wordplay

See More

14 Phobias You Probably Haven't Heard Of

The Longest Long Words List

One-Word Oxymorons: Bittersweet, Spendthrift, and More

Ten Words Ending with a Silent ‘T’

12 Lovely and Unusual Words for the Natural World
See More

Popular

See More

Is that lie 'bald-faced' or 'bold-faced'?

14 Phobias You Probably Haven't Heard Of

The Longest Long Words List
See More

Games & Quizzes

See All
Play Quordle: Guess all four words in a limited number of tries. Each of your guesses must be a real 5-letter word.
Quordle Can you solve 4 words at once?
Play Blossom: Solve today's spelling word game by finding as many words as you can using just 7 letters. Longer words score more points.
Blossom Pick the best words!
Play Missing Letter: a crossword with a twist. Each of the 25 puzzle words start with a different letter of the alphabet. Which letter is missing?
The Missing Letter A daily crossword with a twist
hangman letters and game
Hangman Lightning Round Figure out which word fits in the blanks.
See All