Westmeath (wĕstmēthˈ, wĕstˈmēħ) [key], county (1991 pop. 61,880), 681 sq mi (1,764 sq km), central Republic of Ireland. The county seat is Mullingar. A part of the central plain of Ireland, the region is mostly level and fertile, with many lakes and bogs. The principal river is the Inny, a tributary of the Shannon. Cattle raising is the chief occupation, although wheat, potatoes, and oats are grown. Some textiles are manufactured. Athlone is the largest town. Westmeath was separated from Meath as an independent county in 1543.