A term in instant messenging clients and video games, particularly MMORPGs/-SGs, referring to the general duration a person is away from his/her computer or console while the program/game in question is active and logged on.
Player 1: God! She's always afk
Player 2: Yep, always racking up them frequent idler miles.
Player 1: Lol, she's probably earned enough to redeem a cruise for everyone she's ever passed a glance at.