Answer: megalopolis

AnswerCrossword Clue
MEGALOPOLISSupercity
MEGALOPOLISGiant community
MEGALOPOLISHuge city
MEGALOPOLISHuge conurbation
megalopolisa wide-spreading, thickly-populated urban area
megalopolisvery large city
megalopolisurban region, esp. one consisting of several large cities and suburbs that adjoin each other