(the ancient Drenntia), a river in the south of France, rising in Mont Genève, in the department of Hautes-Alpes, and falling into the Rhone 4 miles below Avignon, after a course of about 160 miles. It flows at first southward, through the departments of the Alps; and then, turning westward, forms the boundary between the departments of Vaucluse and Bouches-du-Rhône. Its chief affluents are the Buëch and the Verdon. The current of the river is rapid, and large quantities of timber are floated down from the mountains, but no part of its course is navigable.