Artesian

Ar·te′sian, a. [F. artésien, fr. Artois in France, where many such wells have been made since the middle of the last century.] Of or pertaining to Artois (anciently called Artesium), in France.

Artesian wells, wells made by boring into the earth till the instrument reaches water, which, from internal pressure, flows spontaneously like a fountain. They are usually of small diameter and often of great depth.