An Etymological Dictionary of the German Language/Kissen
Kissen, Küssen, n., ‘cushion,’ from MidHG. küssen, küssîn, OHG. chussī̆n, n., ‘cushion’; comp. Du. kussen, ‘cushion.’ The G. word is derived (comp. Pfühl and Flaum) from the equiv. MidLat. cussînus (Fr. coussin), which comes from Lat. *culcitinum, allied to culcita, ‘mattress, cushion’; E. cushion and Ital. cuscino are modern Fr. loan-words. The i of ModHG. Kissen comes from MidG. and UpG. dialects (comp. Pilz and Bims).