Clepsydra

Part of speech: noun

Pronunciation: /ˈklɛpsɪdɹə/

Definitions

1. A historical time-measuring device that works by allowing water to flow at a constant rate, originally utilized in various cultures for various purposes
2. An ancient mechanism for chronometry that operates through the controlled outflow of water, impacting disciplines like science and philosophy
3. A device from antiquity used to measure time by the regulated escape of water, which influenced various cultural practices and scientific inquiries

Etymology: The Greek name for this device, "klepsydra," combines "kleptein," meaning "to steal," with "hydor," meaning "water." The name is a bit of a puzzle at first glance, since a water clock does not steal water. The likeliest explanation is that the device was thought of as a water thief, quietly drawing off water drop by drop, and the Greeks applied the image to the way the flow seemed to slip away from the vessel. Water-clock makers in the ancient world used the term for their machines, and the Romans borrowed it directly as "clepsydra." Usage of the word in English follows the Latin form, so the term reached English through the classical tradition rather than through everyday speech. Its survival as a term for a historical instrument reflects how the device itself eventually gave way to mechanical clocks.