A city that serves as the political and administrative center of a country or region; a capital city.
東京は日本の首都であり、経済の中心でもある。
Tokyo is Japan's capital and also its economic center.
各国の首都を地図で確認しよう。
Let's check the capitals of each country on the map.
首都圏は人口が集中している地域だ。
The capital region is an area with a concentrated population.