Pronunciation: (kol'u-sinth),[key] —n. 1. a plant, Citrullus colocynthis, belonging to the gourd family, of the warmer parts of Asia, the Mediterranean region, etc., bearing a round, yellow or green fruit with a bitter pulp.
2. the fruit of this plant.
3. Pharm.the drug derived from the pulp of the unripe but full-grown fruit of this plant, used in medicine chiefly as a purgative. Also called bitter apple(for defs. 1, 2).