An Etymological Dictionary of the German Language/Zins
Zins, m., ‘tribute, rent, (plur.) interest,’ from MidHG. and OHG. zins, m., ‘duty, tribute.’ Borrowed during the OHG. period (comp. Kreuz) from Lat. census (Ital. censo), ‘census, tax.’ The HG. word passed in the form tins into OSax.; in Du., eijns.