mifepristone

noun

mi·​fep·​ris·​tone ˌmi-fə-ˈpri-ˌstōn How to pronounce mifepristone (audio)
mi-ˈfe-pri-ˌstōn
: a drug C29H35NO2 taken orally to induce abortion especially early in pregnancy by blocking the body's use of progesterone

called also RU-486

Examples of mifepristone 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.
More than 100 scientific studies have been conducted looking at the safety and efficacy of mifepristone and misoprostol; all of them have found that the drugs are a safe way to terminate a pregnancy. The Hill, 5 June 2025 An ectopic pregnancy is not caused by mifepristone and should not be considered a serious adverse event. Nicole Brown Chau, CBS News, 4 June 2025 The researchers counted ectopic pregnancy as an adverse event, arguing that doctors should have ruled it out before prescribing mifepristone. Keren Landman, The Atlantic, 24 May 2025 Last summer, the U.S. Supreme Court preserved access to mifepristone. Brittany Carloni, IndyStar, 23 May 2025 See All Example Sentences for mifepristone

Word History

Etymology

perhaps from amino + fe- (alteration of phen-) + pri- (alteration of prop-) + estradiol + -one

First Known Use

1985, in the meaning defined above

Time Traveler
The first known use of mifepristone was in 1985

Browse Nearby Words

Cite this Entry

“Mifepristone.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/mifepristone. Accessed 10 Jul. 2025.

Medical Definition

mifepristone

noun
mi·​fep·​ris·​tone ˌmi-fə-ˈpris-ˌtōn How to pronounce mifepristone (audio) mi-ˈfep-ri-ˌstōn How to pronounce mifepristone (audio)
: a drug C29H35NO2 taken orally to induce abortion especially early in pregnancy by blocking the body's use of progesterone

called also RU-486

More from Merriam-Webster on mifepristone

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