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

When used without mifepristone, a higher dose of misoprostol must be used. — Meghan Bartels, Scientific American, 27 May 2026

The ruling also banned filling a prescription for mifepristone at a retail pharmacy. — Amy Hagstrom Miller, Washington Post, 9 June 2026

If the justices decide the case in Louisiana's favor then mifepristone would no longer be available via telemedicine nationally. — Selena Simmons-Duffin, NPR, 25 June 2026

The bill also prevents the addition of estrogen, mifepristone, and misoprostol — the latter two of which are used to end pregnancies early — to the monitoring program. — Adam Harrington, CBS News, 28 June 2026

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
• hydrocodone
• progesterone
• testosterone
• acetone
• anglophone
• baritone
• bourguignon
• buspirone
• chaperon
• chaperone

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