chuán​yìzhuàn​yì

imperial post service

传驿 傳驛 chuán​yì
imperial post service
The official courier and postal system of imperial China, typically involving a network of relay stations for horses and mail.
传驿 傳驛 zhuàn​yì
relay station
A station or outpost in the imperial courier system used for transferring official documents and changing horses.