twin town
noun [ C ] UK uk/ˌtwɪn ˈtaʊn/ us/ˌtwɪn ˈtaʊn/ (US sister city)
姐妹城，友好城市
a town or city that shares planned activities and visits with a similar town in another country
Cambridge and Heidelberg are twin towns. 剑桥和海德堡结成了友好城市。