反义词是waste，例如：

1、In my view it was a waste of time.依我看，这是浪费时间。

2、It's a waste of time and energy.那是浪费时间和精力。

3、The car was found on a piece of waste ground.那辆车是在一块荒地里发现的。

4、What a waste of paper!多么浪费纸啊！