Primate city

Disproportionately largest city of a country or region

A primate city is a city that is the largest in its country, province, state, or region, and disproportionately larger than any others in the urban hierarchy. A primate city distribution is a rank-size distribution that has one very large city with many much smaller cities and towns and no intermediate-sized urban centers, creating a statistical king effect.

This keyword could refer to multiple things. Here are some suggestions: