Menen (māˈnən) [key], Fr. Menin, commune (1991 pop. 32,645), West Flanders prov., SW Belgium, on the Leie River, near the French border. Manufactures include machinery, textiles, and tobacco products. Founded in 1578, Menen was strongly fortified in the 17th cent. In World War I it changed hands several times during the bitter fighting between German and English forces in the Ypres sector.