The word 公里 (gōnglǐ), meaning "kilometer", is formed by logically combining two existing characters: 公 (gōng), which carries the idea of "common" or "standardized" (as in the metric system being a public, universal standard), and 里 (lǐ), a traditional Chinese unit of distance roughly equivalent to half a kilometer. Thus, the compound directly creates the concept of a "standard li", formally defining the new metric unit by adapting and specifying the familiar traditional measure.