metropolis
n. countable C1 Advanced US //məˈtɹɑpəɫəs// UK //mətɹˈɒpəlˌɪs// me·trop·o·lis
n. a very large, busy, and important city. You use this word to describe a place that is the center of culture or business for a region.
n. a major city or urban area that serves as a significant economic, political, and cultural hub for a country or region.
Tokyo is a massive metropolis with millions of people.
The quiet village was transformed into a bustling metropolis within just a few decades of industrial growth.
Architects in the modern metropolis must balance the need for high-density housing with the preservation of historical landmarks that define the city's unique character.
Usage
Often used with 'sprawling' or 'bustling' to emphasize the scale and activity of the urban environment.