Definition of colocynth:
(n) :
A viny plant, of species Citrullus colocynthis, native to the Mediterranean Basin and Asia. It produces a lemon-sized, yellowish, green-mottled, spongy, and extremely bitter fruit.
(n) :
The powdered pulp of this fruit, a powerful hepatic stimulant and hydragogue cathartic used as a strong laxative.