"AFK" means Away From Keyboard. Away From the Keyboard means you will not be playing/working on the moment. It's a different way of saying you're going somewhere for a few minutes.
An acronym for "ashed, fucked, and kissed". Usually occurs in very toxic relationships in which a boyfriend or girlfriend "ashes" a joint on their significant other, then proceeds to have shitty sex with them. If someone has been AFK'd, they are most likely crazy.
"Yo dude, last night was so much fun, I AFK'd my girl."
Guy: "How'd you get that burn on your arm?"
Girl: "Oh this? My boyfriend AFK'd me when we were 14."
Urbandictionary is full of definitions for this word that say it means "away from keyboard" (in gaming), i.e. the player is inactive, doesn't respond to greetings, such and such. Most of the time, this is what it means.
I would like to give a specific example to further flesh out its meaning: in RuneScape, there is such a thing as "afk training". Literally it's a playing style where you are not literally away from the keyboard or even inactive, you're just doing something on a split screen or paying little attention to what's going on in the game itself as you train your skills, because they are designed to be done "afk", or more accurately, "semi-afk". We just call it afk in this game no matter what.
player1234 is afk... he hasn't been responding to my messages for at least 15 minutes (general example)
rang3r4lyfe is training his firemaking in the most afk way possible, burning protean logs (RuneScape-specific example)
when you are away from your game
AFK = away from keyboard
Selina: "I was AFK! You couldn't kill me! I was making waffles!"
Rob: "I don't care."
AFK means Away from keyboard this is used in games . This is simply to tell someone u will not be playing for a bit and u will be doing something
AFK is a type faster to say "away from keyboard" is an abbreviation, and is more used by people who play games
John is AFK
Jake isn't walking, I think what he is AFK