forerunner

1. N-COUNT If you describe a person or thing as the forerunner of someone or something similar, you mean they existed before them and either influenced their development or were a sign of what was going to happen. 先驅; 前身; 前兆

...a machine which, in some respects, was the forerunner of the modern helicopter. …一臺在某些方面是現(xiàn)代直升飛機的前身的機器。