Source : Webster's Revised Unabridged Dictionary (1913)

Clyster \Clys"ter\, n. [L., fr. G. ?. fr. ? to wash off or out;
   akin to Goth. hl[=u]trs pure, G. lauter: cf. F. clyst[`e]re]
   (Med.)
   A liquid injected into the lower intestines by means of a
   syringe; an injection; an enema.

   {Clyster pipe}, a tube or pipe used for injections.

Source : WordNet®

clyster
     n : injection of a liquid through the anus to stimulate
         evacuation; sometimes used for diagnostic purposes [syn:
         {enema}]