In urban studies, urban primacy indicates the largest city in a country. Such a city is called a primate city

Primate city

A primate city is the leading city in its country or region, disproportionately larger than any others in the urban hierarchy. A 'primate city distribution' has one very large city with many much smaller cities and towns, and no intermediate-sized urban centres, in contrast to the linear 'rank-size...

. In other words, urban primacy can be defined as the central place in an urban or city network that has acquired or obtained a great level of dominance. The level of dominance is measured by population density and the number of functions offered. Higher functions and population will result in higher dominance.