Aquifer

n. underground stratum of rock or gravel which holds water (supplies water for springs, wells, etc.)

An aquifer is an underground layer of water-bearing permeable rock or unconsolidated materials (gravel, sand, silt, or clay) from which groundwater can be usefully extracted using a water well. The study of water flow in aquifers and the characterization of aquifers is called hydrogeology. Related terms include: an aquitard, which is an impermeable layer along an aquifer, and an aquiclude (or aquifuge), which is a solid, impermeable area beneath an aquifer.
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Noun
1. underground bed or layer yielding ground water for wells and springs etc
(hypernym) geological formation, formation

An underground geological formation, or group of formations, containing water. Are sources of groundwater for wells and springs.

A permeable body of rock or regolith that both stores and transports groundwater.