ecumenopolis
noun
ecu·me·nop·o·lis
ˌekyəmə̇ˈnäpələs,
eˌkyüm-
plural -es
: a single city encompassing the whole world that is held to be a possibility of the future
Word History
Etymology
New Greek oikoumenopolis, from Greek oikoumenē world + -o- + -polis