Lompoc (lŏmˈpōk) [key], city (1990 pop. 37,649), Santa Barbara co., S Calif., in an oil and agricultural area; inc. 1888. It has a huge flower-seed industry and two large diatomaceous earth mines. Petroleum and food are processed in the city, and there is light manufacturing. Nearby is La Purisima Mission (1791), a state historic monument. Vandenberg Air Force Base is to the west.