also: かみヤスリ
noun
Abrasive paper used for smoothing surfaces.
木の表面を紙やすりで磨く。
I sand the surface of the wood with sandpaper.
Loanword from English 'sandpaper'; used interchangeably with 紙やすり but slightly more technical or Western-sounding.
Compound of 紙 (かみ, 'paper') and やすり ('file, rasp'). The やすり part is native Japanese; the exact origin of やすり is uncertain.