Today I learned that "rakugaki" means sketch or doodle.

The translation function here (and probably google translate as well) translates that word to "graffiti."

Graffiti is a form of vandalism where people write or draw on public walls without permission.

So I am always very confused when I see that word in topics and comments. It turns out people are just drawing idly on notebooks which makes more sense than committing crimes on walls. 😭