1. Gently stimulating evacuation of the bowels; a laxative.
2. A purging medicine that stimulates evacuation of the bowels.

Used both as a noun; such as, "an aperient is a laxative"; and as an adjective; for example, "prunes are an aperient fruit".

From Latin aperiens meaning "to uncover, to open"; in this case, "to open the bowels".