1. (noun) an abortion-inducing drug (trade name RU_486) 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

• abortion pill
• mifepristone

1. (noun) an abortion-inducing drug (trade name RU_486) 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

• aborticide
• abortifacient
• abortion-inducing drug