HAMM, the capital of a cognominal circle in the Prussian province of Westphalia and government of Arnsberg, on the Lippe, at its confluence with the Ahse, 22 miles N.N.W. of Arnsberg. It is inclosed by walls, but the ditches that formerly surrounded it have been filled up and converted into promenades. Hamm was formerly a member of the Hanseatic League: it has a famous gymnasium, bleach works, manufactures of linen and woollen fabrics, leather, &c., and an active trade in hams. It is situated at the intersection of the Cologne-Minden Railway by that between Munster and Paderborn. Pop. (1849) 6005.