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Related to clepsydra: water clock
n. pl. clep·sy·dras or clep·sy·drae (-drē′)
An ancient device that measured time by marking the regulated flow of water through a small opening. Also called water glass.
n, pl -dras or -drae (-ˌdriː)
(Horology) an ancient device for measuring time by the flow of water or mercury through a small aperture. Also called: water clock
[C17: from Latin, from Greek klepsudra, from kleptein to steal + hudōr water]
clep•sy•dra(ˈklɛp sɪ drə)
n., pl. -dras, -drae (-ˌdri)
[1640–50; < Latin < Greek klepsýdra <kléptein to steal + hýdōr water]
an instrument for measuring time by the controlled flow of water or mercury through a small opening.See also: Instruments, Time