This study examined the lexicalization of economic terminology in North and South Korea through the lens of onomasiological word formation. Unlike previous research that has focused on surface-level lexical differences, this study highlights how identical concepts are realized differently in language. The patterns were categorized into three types: convergence (48%), partial divergence (31%), and divergence (21%). Partial divergence stems from differences in orthographic norms and language purification policies, while full divergence reflects deeper disparities in language policy, economic systems, and ideology. Notably, North Korea’s emphasis on native vocabulary under its "language refinement" and Juche linguistic theory is evident. This research aims to provide a foundation for future efforts toward linguistic integration between the two Koreas.