a stand-in 临时代替者；临时替代者；替身

【例句】
The star had a stand-in for dangerous scenes; we need extra employees for summer fill-ins.
这个明星有一个替身来应付危险场景；我们需要另外的雇。

The lecturer didn't turn up, so we had to find a stand-in.
演讲者没来，因此我们只能找人替代。