Grand Prairie, city (1990 pop. 99,616), Dallas and Tarrant counties, N Tex., halfway between Dallas and Fort Worth; inc. 1909. Located in a highly urbanized and rapidly growing area, the city's boom caused its population to double between 1970 and 1990. Grand Prairie is a distribution center with a large aerospace industry. Other industries include food packaging and the manufacture of tools, machinery, furniture, and electronic and excavating equipment. A nearby auto assembly plant adds to the city's economy. The "Six Flags over Texas" amusement park is nearby.