THORN, a town of Poland, in Regal Prussia, and in the palatinate of Culm. It was formerly an Hanseatic town, and still enjoys great privileges; is large and well fortified; but part of the fortifications, and a great number of houses, were ruined by the Swedes in 1703. It is seated on the Vistula, in E. Long. 19. 22. N. Lat. 52. 56.