urban area; metropolitan area; metropolitan region
Refers to a city and its surrounding commuter belt, often used in urban planning and demographics.
The population of the Tokyo metropolitan area continues to grow.
Traffic congestion is severe in this urban area.
都市圏 is the general term for the metropolitan area of any city, while 首都圏 specifically denotes the region around a capital, usually Tokyo.
Compound of 都市 (city) and 圏 (sphere, area). The exact historical derivation is uncertain, but the term follows standard Sino-Japanese word formation.