Lewis & Short

Altīnum, i, n., = Ἄλτινον, a town in the north of Italy, near Venice, at the mouth of the river Silis, upon the shore of the Adriatic Sea, distinguished for its fat sheep and magnificent villas; now Altino, Mart. 14, 155; Plin. 3, 16, 20, § 118; 3, 18, 22, § 126; cf. Mann. Ital. 1, 85, 86.
Hence, Altīnus, a, um, adj., pertaining to Altinum, Col. 6, 24.
Altīnas, ātis, the same, Col. 7, 2, 3.
Altīnātes, ium, m., its inhabitants, Plin. Ep. 3, 2.