不遗余力英语译为"spare no effort"，这个短语来源于中文语言，意思是不遗余力地去做某事。例句：

I will spare no effort to help you with your homework. 我会不遗余力地帮助你做家庭作业。

She has spared no effort to make her business a success. 她已不遗余力地使她的生意成功。

He is determined to spare no effort to achieve his goals. 他决心不遗余力地实现他的目标。