(n) An underground sleep or level of earth, gravel, or porous rock that yields water.
(n) An underground layer of water-bearing porous stone, planet, or gravel
(n) an underground bed or layer yielding ground-water for wells and springs etc.. The water found in an aquifer are of good age, plus such situations may also be known as fossil liquid.
aquifer in Community Dictionary
an underground level of rock and sand which has water by Keiko ThrashReport definition
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