An Etymological Dictionary of the German Language/Runzel
Runzel, f., ‘wrinkle, fold, rumple,’ from the equiv. MidHG. runzel, OHG. runzila, f.; dimin. of OHG. runza, MidHG. runze, f., ‘wrinkle.’ By inference from OIc. krukka, MidHG. runke, and E. wrinkle (AS. wrincle), the OHG. from runza represents *wrunkza, *wrunkizza, with a dimin. suffix; the loss of the guttural is normal as in Blitz from *blikz, Lenz from *lęnkz. In the non-Teut. languages comp. Lat. rûga, Lith. rùkti, ‘to become wrinkled,’ raúkas, ‘wrinkle’ (see further rauh).