to save up (money)
to save up; to stockpile; to stash away; to hoard; to amass; to salt away
旅行のために、毎月お金を貯めています。
I'm saving money every month for travel.
三年間コツコツ働いてお金を貯めた。
I worked steadily for three years and saved up money.
新しい車を買うためにお金を貯める。
I will save money to buy a new car.