rescuer

n. 救援者

The rescuer called to the men to pay out more rope so that he could go further down the cliff.

营救者向人们喊，要他们把绳子再放长些，好使他能下到崖下。

The one and only way to rescuer him is to lower down a rope.

营救他的唯一办法是往下放一根绳索。