LONGFORD, a county of Ireland, in the province of Leinster, bounded by the counties of Leinster and Cavan on the north, Meath on the east and south, and Roscommon on the west. It contains 143,700 Irish plantation acres, 24 parishes, 6 baronies, and 4 boroughs; and returns 10 members to parliament. It is small, and much encumbered with bog, intermixed with a tolerable good soil; and is about 25 miles long and 15 broad.