Definition of "aquifer"

An aquifer is rock or sediment that holds groundwater – rain that is held below the surface of the soil and collected in empty spaces underground. Aquifers feed rivers to keep their flows at a healthy level, and are also important sources of water when reservoirs or other sources run low.

2023 August 16, Helena Horton, “United Utilities fined £800,000 for taking 22bn litres of water from aquifer”, in The Guardian