ROSTOFF, or Rostow, a large town of the Russian empire, and capital of a territory of the same name, with an archbishop's see, seated on the lake Coteri, in E. Long. 40. 25. N. Lat. 57. 5. The duchy of Rostoff is bounded on the north by Jaroslaw, on the east by Sudal, on the south by the duchy of Moscow, and on the west by that of Tuere.