NSFW is an abbreviation for words like Not Safe For Wife, Not Suitable For Work, but mostly accepted as Not Safe For Work.

It is an internet slang that is often used to describe online posts that are mainly associated with heavy nudity, sexual, heavy profanity and other things that could often link with pornography. Most of the time, NSFW is used for a fandom of some sort when people want to discuss and share the sexual and porno side of the fandom.

The horrible moment when you realise that you have accidentally done something very slightly wrong which has very bad (usually embarassing) implications for you. This is typically the moment of realisation that you just sent a dirty text message to a close member of family, typically your mother, rather than the intended recipient.

Not Safe For Work. Used to describe Internet content generally inappropriate for the typical workplace, i.e., would not be acceptable in the presence of your boss and colleagues (as opposed to SFW, Safe For Work).

Porn/Gore/Censored content.

Short for Not Safe For Work (or Not Suitable For Work), which includes things like: Pornography, gore, fetishes and other shit. If any of your co-workers or your boss finds you watching NSFW, it's gonna be embarrassing and you'll get fired. Watch it at home at your own privacy.

Now Show Friends and Workmates - a suggestion that the viewer draw the attention of friends and/or workmates to their computer screen before following a link or viewing further content. This indicates that the following content is interesting, informative or inspiring, usually in such a way that it will get the viewer promoted and increase workplace productivity.

No, seriously, this shit will get you fired.

Not Safe For Work. Used to describe Internet content generally inappropriate for the typical workplace, i.e., would not be acceptable in the presence of your boss and colleagues (as opposed to SFW, Safe For Work).

basically... porn