Roscommon (114), an inland county of Connaught, SW. Ireland; is poorly developed; one-half is in grass, and a sixth mere waste land; crops of hay, potatoes, and oats are raised, but the rearing of sheep and cattle is the chief industry; the rivers Shannon and Suck lie on its E. and W. borders respectively; there is some pretty lake-scenery, interesting Celtic remains, castle, and abbey ruins, &c. The county town, 96 m. NW. of Dublin, has a good cattle-market, and remains of a 13th-century Dominican abbey and castle.