The Collaborative International Dictionary of English v.0.48:
Purgative \Pur"ga*tive\, a. [L. purgativus: cf. F. purgatif.] Having the power or quality of purging; cathartic. -- n. (Med.) A purging medicine; a cathartic. [1913 Webster]WordNet (r) 3.0 (2006):
purgative adj 1: strongly laxative [syn: cathartic, evacuant, purgative] n 1: a purging medicine; stimulates evacuation of the bowels [syn: purgative, cathartic, physic, aperient]