an arrondissement of the department of the Pas de Calais, in France, extending over 346 square miles, comprehending eight cantons and 144 communes, and containing 119,850 inhabitants. The capital city, of the same name, is on the Brette, and is strongly fortified. It contains 1042 houses, and 6046 inhabitants, who trade in oil, linen, and cheese. Long. 1. 50. E. Lat. 50. 51. N.