save (something) for a rainy day
to keep an amount of money for a time in the future when it might be needed.
She has a couple of thousand pounds kept aside which she's saving for a rainy day.
英语词组固定搭配大全包含18674条英汉双解词组,基本涵盖了全部常用英文词组、短语的翻译及用法,是英语学习的有利工具。