Focus on the pronunciation of megacity
English definition of “megacity”
megacity (plural megacities) (also mega-city, mega city)
/ˈmeɡəˌsɪti/ noun [C]
› a very large city that has a population of more than 10 million people and that is often made of two or more urban areas that have grown so much that they are connected: Lagos is a mega-city that now stretches over roughly 300 square kilometres. London is likely to become one of the world's biggest megacities by 2020.