metropolis
/mɪˈtrɒpəlɪs/noun
1- the capital or chief city of a country or region（国或地区的）首都, 首府; 首要城市。
1.1
- a very large and densely populated industrial and commercial city大都会, 大城市。
词源
late Middle English (denoting the see of a Metropolitan)： via late Latin from Greek mētropolis 'mother state'， from mētēr, mētr- 'mother' + polis 'city'.