[jal.ap] n [F & Sp; F jalap, fr. Sp jalapa, fr. Jalapa, Mexico] (1644) 1 a: the dried tuberous root of a Mexican plant (Ipomoea purga syn. Exogonium purga) of the morning-glory family; also: a powdered purgative drug prepared from it that contains resinous glycosides b: the root or derived drug of plants related to the one supplying jalap
2: a plant yielding jalap