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to pile up; to heap up; to stack up; to put on top of another
to repeat many times over; to go through repeatedly; to accumulate
読み終わった本を棚に重ねて置いた。
I pile books up on the shelf.
失敗を重ねながらも前進する。
Even after repeated failures, keep advancing.
経験を重ねることで成長する。
You grow by accumulating experience.