Căystrŏs or -us, i, m., = Κάϋστρος,
I a river in Lydia , which rises in Mount Tmolus , and falls into the sea at Ephesus , celebrated for the great number of its swans, now Kara - Su : Caystros, Ov. M. 5, 386; Mel. 1, 17, 2: Caystrus, Sen. Q. N. 4, 2, 19; Verg. G. 1, 384; Prop. 3 (4), 22, 15; Ov. M. 2, 253; Plin. 5, 29, 31, § 115.
II —Hence, Căystrĭus , a, um, adj., of Caystros : ales = cygnus, Ov. Tr. 5, 1, 11.