Syn: megalopolis. A very large urban agglomeration. It may be a single city that has simply continued to grow and expand in all possible directions, usually upwards with multiple high-rise dwellings, as well as laterally, sprawling over formerly open countryside as in many American cities; or it may be the fusion of two or more existing cities, as in Tokyo-Yokohama, or the region sometimes called BosWash, in the northeastern United States encompassing Boston, New York, Washington, and various intervening cities, large ones such as Philadelphia and smaller ones such as Hartford and New Haven. Megacities often have outgrown essential infrastructure, including sewers and public transport, and have citizens with multiple social and public health problems.
Subjects: Public Health and Epidemiology.