A district of the province of Khorasan in Persia, formerly called Baihak. It is situated between Nishapur on the east and Shahrud-Bostam on the west, and has a length of about 80 m. and a breadth of 50; its population is about 60,000, and it pays to the government a yearly revenue of £8000. The district has many flourishing villages and much cultivation; it produces much wool, excellent cotton, some silk, partly exported to Russia, partly manufactured into various stuffs in the district, and fruits, exported dried in large quantities. The export trade is chiefly done by a few Russian Armenians who reside in Sabzevar town.