metroplexes

/ˈmɛtrəˌplɛksɪz/
noun
  1. Plural of metroplex; very large metropolitan areas that include several cities and suburbs.
    • Urban planners study how metroplexes develop to improve city living.
    • Many metroplexes around the world are facing challenges with public transportation.
    • The population of some metroplexes has grown faster than the surrounding rural areas.