Friedrich Kluge2507327An Etymological Dictionary of the German Language, I — Insel1891John Francis Davis
Insel, f., ‘island,’ from the equiv. MidHG. insel, insele, f.; formed from Lat. and Rom. insula (Fr. île, Ital. isola); even in OHG. a divergent form of the word, îsila, was borrowed. The OTeut. words for ‘island’ are Aue and Wert.