“空隙”是指两个东西中间的小空间，比如墙上的缝或者时间上的空当。

"空隙" refers to a small space between two things, like a crack in the wall or a gap in time.

我们常说“利用空隙”来做别的事情。

We often say "利用空隙" to mean using the gap to do other things.