Dictionary.com/conurbation:

conurbation (kon-uhr-BAY-shuhn) noun

A predominantly urban region including adjacent towns and suburbs; a metropolitan area.

Source: The American Heritage® Dictionary of the English Language, Fourth Edition
Copyright © 2000 by Houghton Mifflin Company.
Published by Houghton Mifflin Company. All rights reserved.

---

n : an aggregation or continuous network of urban communities [syn: urban sprawl]

Source: WordNet ® 2.0, © 2003 Princeton University