Lewis Short
Fībrēnus (noun M) :
* A small river in Latium, near Arpinum, that flowed around a country seat of Cicero, still called Fibreno or Fiume della Posta, Cic. Leg. 2, 1, 1; 2, 3, 6; Sil. 8, 401.
Charlton T. Lewis, Charles Short, A Latin Dictionary