aqui·​tard ˈa-kwə-ˌtärd How to pronounce aquitard (audio)
plural aquitards
: a geologic formation or stratum that lies adjacent to an aquifer and that allows only a small amount of liquid to pass
If the water level—and thus the pressure—drops enough, water is slowly squeezed out of the large clayey layers—called aquitards—that more or less seal the aquifer, and an aquifer's compression becomes irreversible.Peter Bacque, Richmond (Virginia) Times Dispatch, 14 Nov. 2002

Word History


probably from aqui- (in aquifer) + (re)tard

First Known Use

1965, in the meaning defined above

Time Traveler
The first known use of aquitard was in 1965

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Dictionary Entries Near aquitard

Cite this Entry

“Aquitard.” Dictionary, Merriam-Webster, Accessed 22 May. 2024.

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