unaccounted for

剑桥词典

If a person is unaccounted for, it is not known where they are or whether they are still alive .
（某人）生死未知的
A fire on the ship killed a hundred or more passengers - some likely victims are still unaccounted for. 船上的大火让一百多名乘客丧生，可能还有些人生死未知。

If something such as an amount of money is unaccounted for, it is not present and there is no explanation for what has happened to it.
（金钱）找不到的，去向不明的
An audit of the police department found that $100,000 in cash and one handgun were unaccounted for. 对警察局进行的审计发现有10万美元现金和一支手枪去向不明。 返回 unaccounted for