Lewis & Short

Ăchĕrūsĭa, ae, f. [Acheruns].

  1. I. Acherusia Palus,
    1. A. A lake in Epirus, through which the Acheron flows, Plin. 4, 1, 1.
    2. B. A lake in Campania, between Misenum and Cumae, now Lago di Fusaro, Plin. 3, 5, 9.
  2. II. A cave in Bithynia, from which Cerberus is said to have been dragged, Mel. 1, 19, 7; Plin. 6, 1, 1; the same called Ăchĕrūsĭs, ĭdis, f., Val. Fl. 5, 73.