An Etymological Dictionary of the German Language, T (1891)
by Friedrich Kluge, translated by John Francis Davis
traun
Friedrich Kluge2509036An Etymological Dictionary of the German Language, T — traun1891John Francis Davis

traun, interj., ‘truly! in faith! forsooth!’ from the equiv. MidHG. (MidG.) trûn, trûwen, for MidHG. triuwen, entriuwen, ‘in truth,’ allied to Treue.