Final answer:
The term that describes groundwater confined and rising in a well due to pressure is 'artesian'. This occurs when permeable rock layers are sandwiched between less permeable layers, causing pressurization that can naturally drive water up a well.
Step-by-step explanation:
The term you are looking for to describe groundwater that is confined and rises in a well because it is under pressure is artesian. Such conditions occur when a water-bearing, permeable rock layer is trapped between two less permeable rock layers. If this layer is inclined, water will flow into the lower part of the permeable layer and become trapped, thus creating pressure. When a well is drilled into such an area of confinement and reaches the pressurized zone, water is forced up, sometimes to the surface, without pumping. This is due to the natural pressure from the higher level pushing the water downward. Artesian wells are particularly useful as they can sometimes deliver water to the surface without the need for mechanical pumps.