What is the meaning of Metropolitan_city?

A large city that is the center of a metropolitan area; a metropolis.

In India, a city at the center of a metropolitan area, which in this context is defined in the Constitution of India as "an area having a population of ten lakhs [one million] or more, comprised in one or more districts and consisting of two or more Municipalities or Panchayats or other contiguous areas, specified by the Governor by public notification to be a Metropolitan area for the purposes of this Part". See List of metropolitan areas in India.

In Italy, a special type of province that contains a large city at its core. See Metropolitan cities of Italy for a list.

In South Korea, a particular class of large cities. See Metropolitan cities of South Korea for a list.

Source: wiktionary.org