General medical definition: A drug which causes the interruption of a pregnancy and the death of an embryo or fetus. (Pregnancy begins when the pre-embryo attaches to the wall of the uterus.) Common pro-life definition: A drug which causes the death of any form of human life after conception. The difference in definitions makes dialog concerning emergency contraception (a.k.a. the morning after pill) very difficult. More info.
medication which terminates pregnancy and induces an abortion. Since the pro-life movement defines the start of pregnancy differently from that used by the pro-choice movement and the medical profession, a medication can be considered as an abortifacient by pro-lifers and a contraceptive by everyone else.