a space from which most or all of the matter has been removed, or where there is little or no matter

a lack of something

The withdrawal of troops from the area has created a security vacuum which will need to be filled. 部队撤军之后，那个地区出现了一个有待填补的安全真空。

kept separate from other people and activities

No artist works in a vacuum - we are all of us influenced by others. 没有哪个艺术工作者可以脱离现实——我们都受到他人的影响。

a vacuum cleaner

to use a vacuum cleaner to collect dust, dirt, etc.

Vacuum (up) the cake crumbs, would you? 请用吸尘器把面包屑清理掉，好吗？