clep·​sy·​dra | \ ˈklep-sə-drə How to pronounce clepsydra (audio) \
plural clepsydras or clepsydrae\ ˈklep-​sə-​ˌdrē How to pronounce clepsydrae (audio) , -​ˌdrī \

Definition of clepsydra

Did You Know?

In ancient times the sun was used to measure time during the day, but sundials weren't much help after dark, so peoples around the world invented clocks that used dripping water to mark the hours. In one kind of water clock, possibly invented by the Chaldeans, a vessel was filled with water that was allowed to escape through a hole. The vessel's inside was marked with graduated lines, and the time was read by measuring the level of the remaining water. The ancient Greeks called their water clocks "klepsydra" ("water thief"), which comes from "kleptein" ("to steal") and "hydōr" ("water"). English speakers stole "clepsydra" from the Greeks in the 16th century, but actual water clocks have become increasingly rare.

First Known Use of clepsydra

1580, in the meaning defined above

History and Etymology for clepsydra

Latin, from Greek klepsydra, from kleptein to steal + hydōr water — more at klepto-, water

Keep scrolling for more

Learn More about clepsydra

Time Traveler for clepsydra

Time Traveler

The first known use of clepsydra was in 1580

See more words from the same year

Listen to Our Podcast about clepsydra

Statistics for clepsydra

Cite this Entry

“Clepsydra.” Dictionary, Merriam-Webster, Accessed 1 Jun. 2020.

More from Merriam-Webster on clepsydra

Thesaurus: All synonyms and antonyms for clepsydra Encyclopedia article about clepsydra

Comments on clepsydra

What made you want to look up clepsydra? Please tell us where you read or heard it (including the quote, if possible).


See Definitions and Examples »

Get Word of the Day daily email!

Test Your Vocabulary

May 2020 Words of the Day Quiz

  • a blooming wisteria tree
  • Which is a synonym of exiguous?
Spell It

Can you spell these 10 commonly misspelled words?

Add Diction

Test Your Knowledge - and learn some interesting things along the way.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!