Oise, a river and department in northern France. The former rises by two streams, one of which has its source near Rocroy in the Ardennes, the other near Chimay, in Belgium. Flowing S.W., past Guise, Chauny, Compiegne, and Pontoise, it joins the Seine near Conflans, after a course of about 150 miles. The department is bounded N. by Somme, S. by Seine-et-Marne and Seine-et-Oise, E. by Aisne, and W. by Eure and Seine Inferieure. It has an area of 2,260 square miles. The chief products are wheat and other cereals, beet-root, colza, hemp, flax, vegetables, fruit, milk, meat, cider, and wine of poor quality. There are large iron-works at Montataire, lace-works at Chantilly, clock and carpet factories at Beauvais, and woollen mills at various places.