资料来源 : Webster's Revised Unabridged Dictionary (1913)

Cathartic \Ca*thar"tic\, n. [Gr. ?.] (Med.)
   A medicine that promotes alvine discharges; a purge; a
   purgative of moderate activity.

   Note: The cathartics are more energetic and certain in action
         that the laxatives, which simply increase the tendency
         to alvine evacuation; and less powerful and irritaint
         that the drastic purges, which cause profuse, repeated,
         and watery evacuations. -- {Ca*thar"tic*al*ly}, adv. --
         {Ca*thar"tic*al*ness}, n.