forerunner
/ˈfɔːˌrʌnə(r)/noun
1- a person or thing that precedes the coming or development of someone or something else前驱, 先驱, 先导：
the ice safe was a forerunner of today's refrigerator.
冰柜是现代电冰箱的先导。
1.1
- a sign or warning of something to come前兆, 预兆, 征兆：
overcast mornings are the sure forerunners of steady rain.
阴暗的早晨预示着肯定会有连绵阴雨。
1.2
- archaic an advance messenger〈古〉先遣报信者。