noun
sketchbook; scribble pad
A notebook or pad used for casual drawing, doodling, or scribbling.
子供の頃、落書き帳に漫画をよく描いていた。
When I was a child, I often drew comics in my sketchbook.
会議中、落書き帳に落書きをしていた。
During the meeting, I was doodling on a scribble pad.
Compound of 落書き (doodle, scribble) and 帳 (notebook, register).