SLUCZK, a large and populous town in Poland, in Lithuania, and capital of a duchy of the same name; famous for three battles gained here, by Constantine duke of Ostrog, over the Tartars, in the reign of Sigismund I. It is seated on the river Sluczk, 72 miles south-east of Minsk, and 70 south of Novogrodek. E. Long. 28. 24. N. Lat. 52. 36.