A person who has worked in the same company or position for so long that they no longer give a crap. The company could collapse in bankruptcy all around them, and they would just shrug their shoulders and get another cup of coffee. For some, being fired or laid-off would almost be a relief. For others, they are just marking their time until retirement.
Coworker1: Hey, did you hear about the error Brad caused that crashed the network this morning?
Coworker2: Yeah, I heard about it, Jen. Do you think it's serious enough for management to give him the axe?
Coworker1: Maybe, but I don't think he gives a crap. I just saw him earlier playing solitaire!
Coworker2: Damn Long Timer!