'artesian' originates from French, specifically the word 'artésien', which referred to the province name 'Artois' (a region in northern France) and meant 'of Artois'.

'artesian' entered English via Middle French 'artésien' (meaning 'from Artois'), the term being applied in the 17th century to wells in that region noted for water rising under pressure; the regional name 'Artois' itself comes from older Latin/medieval forms referring to that province.

Initially it meant 'of or from Artois' (the French province), but over time it evolved to mean 'relating to a well or water that rises under natural pressure', the geographic sense becoming specialized into a hydrogeological sense.