metropolis

A major city, especially the chief city of a country or region.

A city or an urban area regarded as the center of a specific activity.

The chief see of a metropolitan bishop.

The mother city or country of an overseas colony, especially in ancient Greece.

In ancient Greece, the mother city or parent state of a colony, as Corinth of Corcyra and Syracuse, or Phocæa of Massalia (Marseilles), the colony being independent, but usually maintaining close relations with the metropolis.