mifepristone

noun

mi·​fep·​ris·​tone ˌmi-fə-ˈpri-ˌstōn 

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

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

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

Rhymes for mifepristone

• aldosterone
• anticyclone
• progesterone
• testosterone
• acetone
• anglophone
• baritone
• bourguignon
• buspirone
• chaperon
• chaperone
• cobblestone

Medical Definition

mifepristone

noun

mi·​fep·​ris·​tone ˌmi-fə-ˈpris-ˌtōn  mi-ˈfep-ri-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