Megalopolis (noun)

1. A very large city, especially one consisting of a metropolitan area and its suburbs.
2. A group of several very large cities and their suburbs that form a continuous urban area.

Origin:

Derived from greek μέγας (megas) 'large' + πόλις (polis) 'city'.

Examples:

1. The megalopolis of Tokyo-Yokohama is the largest metropolitan area in the world.
2. The northeast region of the United States is known as the Boston-Washington megalopolis.
3. The megalopolis of Mexico City is one of the largest metropolitan areas in the world.
4. The urban sprawl of the Los Angeles megalopolis is a well-known example of suburbanization.
5. The megalopolis of Shanghai, China is a leading center of economy and culture in Asia.