Artesian water

A well tapping a confined or artesian aquifer in which the static water level stands above the top of the aquifer. The term is sometimes used to include all wells tapping confined water. Wells with water level above the water table are said to have positive artesian head (pressure), and those with water level below the water table have negative artesian head.


Source: Handbook of water and wastewater treatment plant operations

Wikipedia: https://en.wikipedia.org/wiki/Artesian_aquifer