a walled town of the kingdom of Sardinia, in Italy, the capital of the province of Lomellina, is situated on an eminence on the right bank of the Arboagna, which is here crossed by a bridge, 14 miles S.S.E. of Novara. The principal buildings are,—three churches, a courthouse, a theatre, several schools, and an hospital. There is some trade in rice, grain, and silk. The situation of the town is unhealthy; and from this circumstance it is said to derive its name, being a corruption of mortis ara. Another account, however, derives this name from the battle fought here in 774 A.D., when the Lombards were defeated by Charlemagne with great slaughter. Pop. 5316.