CLONSAST, or CLONCAST, also called CLON BOLLOGUE, a parish, in the barony of COOLESTOWN, KING'S county, and province of LEINSTER, 6- miles (N. E. by E.) from Portarlington ; containing 3914 inhabitants, and comprising about 25,000 statute acres, of which about 14,000 are cultivable, the remainder bog. The living is a rectory, in the diocese of Kildare, united in 1796, by act of council, to the vicarage of Ballynakill, forming the union of Clonsast, in the alternate patronage of the Duke of Leinster and the Bishop : the tithes amount to £628. 12. 3-., and of the union to £694. 3. 0-. The church is a plain building, to the repairs of which the Ecclesiastical Commissioners have recently granted £243. In the R. C. divisions the parish is the head of a union or district, called Clonbollogue, comprising this parish and parts of those of Geashill and Ballynakill, in which are chapels at Clonbollogue and Brackna, and the Island chapel. The parochial school is aided by an annual donation from the incumbent ; and there is a school at Clonbollogue. In these schools about 250 children are educated ; there are also four private schools, in which are about 110 children.