abortifacient; abortion-inducing drug
A drug used to induce abortion. This is a specific medical term; in everyday language, people may use more general expressions like 中絶薬.
In the past, some plants were used as abortifacients.
Compound of 下ろし (from 下ろす, 'to bring down; to abort') and 薬 ('medicine'). The exact historical derivation is uncertain.