an arrondissement of the department of the Oise, in France, which extends over 516 square miles. It contains seven cantons and 132 communes, with, in 1836, 78,790 inhabitants. The capital is the city of the same name, situated on the river Nonette, an ancient place, with walls built at some remote period. The cathedral is also antique, and has the loftiest tower in France. It contains nine churches, and 950 houses, with 5016 inhabitants.