Toyama (tōyäˈmä) [key], city (1990 pop. 321,254), capital of Toyama prefecture, W central Honshu, Japan, on Toyama Bay. It is the main center of Japan's patent medicine industry and also has industries that produce chemicals and textiles. Toyama prefecture (1990 pop. 1,120,182), 1,644 sq mi (4,258 sq km), is a rice-growing area with many rivers that provide hydroelectric power for industry.