San DiegoSan Di·e·go
seaport in S Calif.
Origin of San Diegoafter San Diego (St. Didacus), 15th-c. Spanish friar
A city of southern California on San Diego Bay, an inlet of the Pacific Ocean near the Mexican border. Founded as a Spanish mission in 1769, the city grew as a port after the coming of the railroad in the 1880s.x