ADOUR, the ancient Aturus, a river of France which rises near Barége, in the department of Upper Pyrenees, and, flowing first northwards, then with a circuit to the west, passes through the departments of Gers and Landes, and falls into the Bay of Biscay 3 miles below Bayonne. Its length is about 180 miles, and it is navigable for about 70 miles, as far as St Séver. Bagnères-de-Bigorre, Tarbes, and Dax are the other important towns on its banks.