not moving or not able to move

The inert figure of a man could be seen lying in the front of the car. 可以看到一个男人躺在汽车前座上，一动也不动。

not energetic or interesting

The narrative is inert and sloppy, as if the author had been writing half-asleep. 这个故事既没意思又无条理，好像作者是在半睡半醒中写的。

Inert substances do not produce a chemical reaction when another substance is added.

inert gases 惰性气体