to save sth, especially money, for a time when you will really need it
SAVE, KEEP, ETC. STH FOR A RAINY DAY
Meaning of SAVE, KEEP, ETC. STH FOR A RAINY DAY in English
Oxford Advanced Learner's English Dictionary. Оксфордский английский словарь для изучающик язык на продвинутом уровне. 2005