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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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.

Noun
1. underground bed or layer yielding ground water for wells and springs etc
(hypernym) geological formation, formation