abortifacient

any instrument, medicine, drug, or any other substance or device which is known to cause fetal death when employed in the usual and customary use for which it is manufactured, whether or not the fetus is known to exist when such substance or device is employed.

Defined by the Supreme Court in Diamond v. G Charles, 476 U.S. 54 (1986).

In medical jurisprudence. A drug or medicine capable of or used for, producing abortion.