Clepsydra

Clepsydra may refer to:


 * Clepsydra, an alternative name for a water clock.
 * In ancient Greece, a device (now called a water thief) for drawing liquids from vats too large to pour, which utilized the principles of air pressure to transport the liquid from one container to another.
 * Clepsydra Geyser in the Lower Geyser Basin of Yellowstone
 * Clepsydra (diatom), a genus of protists
 * Klepsydra well on the Akropolis.