noun
urban subcenter; secondary city center
Used in urban planning and geography to refer to a secondary hub within a large city that relieves pressure on the main center. Common in discussions of Tokyo's development, e.g., Shinjuku, Shibuya, Ikebukuro.
新宿は東京の副都心の一つです。
Shinjuku is one of Tokyo's urban subcenters.
副都心の開発計画
A development plan for the subcenter was announced.