Definition of "camerlengo"

Benedict will also stop using the so-called fisherman’s ring to seal documents. It will be destroyed by the cardinal camerlengo, the acting head of state of Vatican City during the “sede vacante,” the canon law term used when the papacy is vacant.

2013 February 26, Gaia Pianigiani, Elisabetta Povoledo, “Benedict XVI to Be Known as Emeritus in Retirement”, in New York Times‎