Is the word "masturbation" NSFW?

My question, “Is 9 years old too young to know about masturbation?” is currently modded because I’m required to have NSFW on the title.

Do you agree that “masturbation” is a “dirty” word, unsuited to work?

Is that what you understood “NSFW” to mean, of be used for?

I’m not annoyed, irritated or bothered by this question in any way, shape or form. I just thought it was interesting and wanted to discuss it before I changed my question.

I have to admit that I never considered putting NSFW on the question when I wrote it.