aqui·​tard | \ ˈa-kwə-ˌtärd How to pronounce aquitard (audio) \
plural aquitards

Definition of aquitard

: 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

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First Known Use of aquitard

1965, in the meaning defined above

History and Etymology for aquitard

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

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The first known use of aquitard was in 1965

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Cite this Entry

“Aquitard.” Dictionary, Merriam-Webster, Accessed 14 May. 2021.

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