El Segundo (ĕl sēgŭnˈdō) [key], industrial city (1990 pop. 15,223), Los Angeles co., S Calif., on Santa Monica Bay; inc. 1917. Its products include navigation and computer systems, aircraft parts, office machines, telephone apparatus, and refined oil products. There is also aerospace research. It was founded (1911) as an oil town. A U.S. air force missile station is there. The Los Angeles international airport is adjacent to the city.