Clēp'sy-drā or Clēp-sy'drā, n.

(Syn-op., § 130), n. [Lat. clepsydra, Gr. κλεψύδρα, from κλέπτειν, to steal, conceal, and ὕδωρ, water.] 1. A water-clock; a contrivance used anciently for measuring time by the gradual discharge of water from a small aperture, as if by stealth. W. Smith. 2. A chemical vessel. Johnson. Clepsydra, (1.)