メガロポリス

noun

megalopolis

A very large, heavily populated urban complex, often formed by the merging of several cities. Used in geography and urban studies.

• 東とう京きょうから大おお阪さかにかけての地ち域いきは、世せ界かい有ゆう数すうのメガロポリスだ。

  The area from Tokyo to Osaka is one of the world's leading megalopolises.