Lewis & Short

Euxīnus, a, um, adj., = Εὔξεινος (hospitable), an epithet of the Black Sea. Usually connected with Pontus. In Ovid also freq.: Euxinum mare, Ov. Tr. 4, 8, 42; 4, 10, 97; 5, 10, 2; id. Pont. 4, 6, 46; cf. aequor, id. Tr. 5, 2, 63: aquae, id. Pont. 2, 6, 2: fretum, id. ib. 2, 2, 2: undae, id. ib. 4, 8, 1: vada, id. ib. 4, 9, 2: litus, id. Tr. 5, 10, 13; id. Pont. 4, 3, 51.
And absol.: Euxīnus, i, m. (sc. Pontus), Ov. Tr. 2, 197; 4, 1, 60.