godan verb (-su)
pile up like a mountain; form a huge pile
Describes things accumulating or being heaped up in a large, mountain-like pile. Often used for snow, goods, or work.
雪が山なすほど積もった。
The snow piled up as high as a mountain.
書類が机の上に山なしている。
Papers are piled up on the desk like a mountain.
Standard spelling; the verb なす is written in kana to distinguish from other kanji for なす.
Alternate kanji spelling using 成す; less common and may be considered non-standard.
Compound of 山 (mountain) and なす (to form, to make). The verb なす is an older form of する, and the phrase literally means 'to make into a mountain'.