A Navy acronym (Lazy, Inefficient Fucker Expecting Retirement) used to describe someone who does as little as humanly possible and is just waiting to collect his or her pension.
"That O'Hara is such a fucking lifer. He's so lazy, I bet it's an effort for him to turn in his sleep. Jesus! That fucker moves so slowly you have to look twice just to see if he's moving at all!"
"You're telling me. I heard he's so lazy he married a woman who was pregnant by someone else."