certain

The population explosion is certain to cause widespread famine.

人口激增必然会引起大范围的饥荒。

I had lunch today with a certain George Michael - not the George Michael, I should explain.

我今天和一位叫乔治‧迈克尔的人共进了午餐——我得说明一下，不是那个乔治‧迈克尔。