Col"ocynth (?), n. [L. colocynthis, Gr. &?;. Cf. Coloquintida.] (Med.) The light spongy pulp of the fruit of the bitter cucumber (Citrullus, or Cucumis, colocynthis), an Asiatic plant allied to the watermelon; coloquintida. It comes in white balls, is intensely bitter, and a powerful cathartic. Called also bitter apple, bitter cucumber, bitter gourd.