An abortion-inducing drug (trade name Mifepristone) developed in France

• When taken during the first five weeks of pregnancy it blocks the action of progesterone so that the uterus sloughs off the embryo

Wiktionary Word definitions in Wiktionary
n. (context steroid drug English) A steroid pharmaceutical used to induce abortion, or as an emergency contraceptive.

Wikipedia Word definitions in Wikipedia
Mifepristone , also known as RU-486 , is a medication typically used with misoprostol to bring about an abortion . This combination is more than 95% effective during the first 50 days of pregnancy . It is also effective in the second trimester of pregnancy. ...