Merriam-Webster Collegiate Dictionary - clyster

 noun  Etymology: Middle English, from Middle French or Latin; Middle French clistere, from Latin ~, from Greek klyster, from klyzein to wash out; akin to Welsh clir pure, Old English hlutor clean  Date: 14th century enema CLYTEMNESTRA  noun  Etymology: Latin, from Greek Klytaimnestra  Date: 15th century the wife and murderess of Agamemnon