A Metropolis

1. (historical, especially Ancient Greece) The mother (founding) polis (city state) of a colony. Synonyms: mother city, metropole
2. A large, busy city, especially as the main city in an area or country or as distinguished from surrounding rural areas. Coordinate term: capital city
3. (canon law) The see of a metropolitan archbishop, ranking above its suffragan diocesan bishops.Synonym: archbishopric
4. (ecology) A generic focus in the distribution of plants or animals.