In a first person shooter, when you go away from keyboard for just a second to do something, and come back to find yourself dead in-game. Common modes of death include being sniped or simply run up to with a melee weapon.
"Dude. You just stood still for a second and a sniper got you."

"Shit! I was just opening a bag of Cheetos!"

"Must've been an AFK Assassination."
by AlpineWolf April 14, 2010
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