The Collaborative International Dictionary of English v.0.48:
Enema \En"e*ma\, n.; pl. L. Enemata. [L. enema, Gr. ?, fr. ? to send in; ? in + ? to send.] (Med.) An injection, or clyster, thrown into the rectum as a medicine, or to impart nourishment. --Hoblyn. [1913 Webster]WordNet (r) 3.0 (2006):
enema n 1: an injection of a liquid through the anus to stimulate evacuation; sometimes used for diagnostic purposes [syn: enema, clyster]