clepsydra definition by Webster's New World
Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio. Used by arrangement with John Wiley & Sons, Inc.
clepsydra definition by American Heritage Dictionary
noun pl. clep·sy·dras or clep·sy·drae
An ancient device that measured time by marking the regulated flow of water through a small opening. Also called water glass.
Origin: Latin, from Greek klepsudra : kleptein, kleps-, to steal + hudōr, water; see wed-1 in Indo-European roots.