fentanyl

noun

fen·​ta·​nyl ˈfen-tə-ˌnil 

: 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

Drug dealers often mix fentanyl with other substances, such as heroin, methamphetamine or cocaine, because of its potency and low cost. —Rosalio Ahumada, Sacbee.com, 15 Dec. 2025

The president's executive order describes illicit fentanyl as fentanyl that is manufactured, distributed, dispensed or possessed in violation of the Controlled Substances Act. —Kathryn Watson, CBS News, 15 Dec. 2025

However, the target vessels in the Caribbean are believed to be carrying cocaine, not the far more deadly fentanyl, according to lawmakers who were briefed on the strikes. —Filip Timotija, The Hill, 13 Dec. 2025

In that same time period Border Patrol seized over 16,600 pounds of marijuana, over 473 pounds of cocaine, over 145 pounds of heroin, over 8,224 pounds of methamphetamine, and over 3,079 pounds of fentanyl. —Brandon Loomis, AZCentral.com, 13 Dec. 2025

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

Medical Definition

fentanyl

noun

fen·​ta·​nyl ˈfent-ᵊn-ˌil 

: 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.