a player in a FPS (or any other multiplayer game which involves fast action and guns) who sits back as other players duke it out in a firefight, and makes an appearance after the victor of the duel is left with a little amount of health and kill him/her for an easy kill. Much like a janitor cleans up after a mess.
Dude, its no fun playing Halo with you anymore because all you do is janitor with your assault rifle.
1. People with huge beards in your school that cleans up after your shit, but in reality, they are the rulers of the world. Usually old people with a crazed look in his eyes, they are very wise and the only mens on the planet able to make babies.
2.He's your dad.
1. Voter 1: Hey, is George Bush a janitor?
Voter 2: Nah he's too dumb to be one. Osama is a real janitor. Look at the size of his beard!
When a girl is giving you a blow job, and just as you are about to ejaculate, you whip your penis out of her mouth and jizz all over the ground. Then you mop it up with her hair and throw her down a flight of stairs.
Jim: Wow jake, you really gave her a good janitor. you should be a real janitor.
Jake: I thought mopping up my jizz with ur mom's hair made me a real janitor (sobs)