noun
eraser dust; eraser shavings; eraser crumbs
The small bits of rubber or debris left after using an eraser.
消しクズを机から払った。
I brushed the eraser dust off the desk.
消しクズがノートにたくさんついている。
There are a lot of eraser crumbs on the notebook.
消しゴム is the eraser itself, while 消しクズ refers to the debris it produces.
Compound of 消し (keshi, 'erasing', from 消す) and クズ (kuzu, 'waste, scraps'). The katakana spelling クズ is often used to avoid the kanji 屑, which can carry a negative connotation.