Oceanside. 1 City (1990 pop. 128,398), San Diego co., S Calif., on the Gulf of Santa Catalina; inc. 1888. It is a commercial and trading center for an inland farm area and for nearby Camp Pendleton, a huge U.S. marine corps amphibious base. Mainly residential, the city produces rubber goods, electronic components, hardware, motors, and clothing; it also has a large citrus, flower, and bulb industry. Deep-sea fishing and tourism, owing to its seaside location, are also important. The city has undergone major redevelopment since the 1990s. It is the home of the California Surf Museum, and nearby is San Luis Rey Mission (founded 1798). 2 Uninc. resort city (1990 pop. 32,423), Nassau co., SE N.Y., on the south shore of Long Island.