Ain

Ain (a department of Auvergne-Rhône-Alpes, France); Ain (a river in the Jura and Ain departments, in eastern France, flowing from the Jura Mountains into the Rhône River)

Named after the River Ain, from Medieval Latin Hinnis, from earlier Igneus, of pre-Roman, probably Celtic, origin; perhaps Proto-Celtic *inn, itself likely related to the river River Inn (Latin Aenus), both related to *enios (“water”), ultimately from Proto-Indo-European *h₁ey- (“to go”), found in many placenames such as the settlement Aenona.