An Etymological Dictionary of the German Language/Annotated/Jahn

by Friedrich Kluge

Jahn, masculine, ‘swath,’ first found in early Modern High German, yet undoubtedly a genuine German word, existing throughout South Germany (Middle High German *jân), and also appearing in Swedish dialects as ån. In Swiss dialects Jahn means ‘passage (formed by a swath)' Hence the word is a derivative of the Aryan root yê, or rather ĭ, ‘to go,’ with which Gothic iddja, ‘went’ (Sanscrit yâ, ‘to go’), is connected. See gehen and eilen.