understudy

When the play's star broke her leg her understudy wept crocodile tears.

当这部剧的主演摔坏了腿时，她的替角流下了鳄鱼的眼泪。

While the star is recuperating from her illness, her role will be played by her understudy.

当明星正在休养恢复健康时，她的角色由修补演员代替。