sister city
noun🔊/ˌsɪstə ˈsɪti/
🔊/ˌsɪstər ˈsɪti/
(North American English) (British English twin town)
one of two towns or cities in different countries that have a special relationship with each other Okayama is San Jose's sister city in Japan. 冈山是日本圣何塞的姊妹城市。