Charlton T. Lewis, Charles Short, A Latin Dictionary

I.a small river in the neighborhood of Alba Longa, near the modern Marino, at the source of which there was a grove sacred to the deity Ferentina (perh. the same as Diana); “here the Latini used to hold their general assemblies: ad caput aquae Ferentinae,” Liv. 1, 51, 9; for which: ad caput Ferentinae, Cinc. ap. Fest. p. 241, 12 Müll. N. cr.; and: “ad caput Ferentinum,” Liv. 2, 38; cf.: “ut ad lucum Ferentinae conveniant,” id. 1, 50; so id. 1, 52, 5; 7, 25, 5. (This place is different from Ferentinum, the city of the Hernici; see the foll. art.).