A person who spends a massive amount of time doing something that wont benefit their life at all, Such as a person who plays Call of duty: Modern Warfare2, 24/7.
John:Dude, All this month i played COD and only slept like 4 times.

James:Dude.... Are you for real?

John:Yeah, Man!

James:You're a real low lifer, Bro.
by A member of Anon. September 22, 2010
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