'Water clock' definitions:
Definition of 'water clock'
From: WordNet
noun
Clock that measures time by the escape of water [syn: water clock, clepsydra, water glass]
Definition of 'Water clock'
From: GCIDE
- Water clock \Wa"ter clock`\ An instrument or machine serving to measure time by the fall, or flow, of a certain quantity of water; a clepsydra. [1913 Webster]