Synonyms

mifepristone

American

[mif-uh-pris-tohn] / ˌmɪf əˈprɪs toʊn /

noun

an antigestational drug, C 29 H 35 NO 2 , that prevents a fertilized egg from attaching to the uterine wall by blocking the action of progesterone.

mifepristone British

/ mɪˈfɛprɪˌstəʊn /

noun

an antiprogestogenic steroid, used in the medical termination of pregnancy. Formula: C 29 H 35 NO 2

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of mifepristone

1985–90; probably alteration of (a)mi(no)phe(nol) + pr(opyl) + est(radiol) + -one

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

A lower court in Louisiana also required the FDA to give an update by October on a promised review of the safety regulations governing mifepristone.

From The Wall Street Journal • Jun. 5, 2026

In addition to the FDA study using the agency’s own drug safety systems, the agency is also considering hiring a contractor to acquire and analyze data on mifepristone use, the administration officials said.

From The Wall Street Journal • Jun. 5, 2026

On this week’s Amicus, Dahlia Lithwick and Mark Joseph Stern dive into the legal battle over mifepristone, the medication that can be used for abortion care.

From Slate • May 21, 2026

If mifepristone is difficult to obtain, a misoprostol-only medication abortion still works.

From Salon • May 15, 2026

The two-drug protocol is also used to manage miscarriage, but Brandi fears the legal wrangling over mifepristone is creating "stigma."

From Barron's • May 10, 2026

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023