- (text messaging, computing, military, Internet slang) Initialism of away from the keyboard (that is, away from one's computer)
1989 May 8, Vince Perriello (Editor in Chief), “Volume 6, Number 19”, in FidoNews, archived from the original on 2005-01-18:
AFK - Away From Keys
1990 January 17, Russ Armadillo Coffman, “Smilies collection”, in rec.humour, Usenet, retrieved 2016-06-26, message-ID <email@example.com>:
AFK = Away From Keyboard
- (shooting games) Initialism of a free kill.