1To accumulate or save gradually (transitive), often used for regularly setting aside money (e.g., savings plans).
毎月給料の一部を別口座に積み立てている。
I set aside part of my salary into a separate account every month.
子どもの教育資金を積み立てるために保険に入った。
I took out an insurance policy to save up for my child's education.
ポイントを積み立てて商品と交換した。
I accumulated points and exchanged them for a product.