LOMSHA, or LOMZA, a town of Russian Poland, capital of a cognominal circle in the government of Augustovo, on the left bank of the Narew, a tributary of the Vistula, 94 miles N.N.E. of Warsaw. It is situate in a wooded valley, and contains some spacious and well-paved streets. The principal buildings are, an arsenal, a Piarist college, a gymnasium, and several churches and convents. The manufactures are chiefly confined to iron and paper. Pop. (1854) 5804.