noun
wastepaper; scrap paper
Paper that is no longer needed and is to be discarded or recycled. Often used in contexts like shredding or bundling old documents.
See also: 反故 (ほご)
反故紙をシュレッダーにかける。
I put the wastepaper through the shredder.
机の上に反故紙が散らかっている。
Scrap paper is scattered on the desk.
反故 is a broader term for wastepaper or something rendered useless, while 反故紙 specifically refers to wastepaper as a material.
Compound of 反故 (ほご, 'wastepaper' or 'something useless') and 紙 (かみ, 'paper'). The exact origin of 反故 is uncertain, but it has been used since the Edo period to refer to discarded paper.