From the Greek (nou-) para- lazy; + botti - bum. Someone who makes out they're too ill to do anything when they're at home and then when they get out the front door they're fit and healthy all of a sudden!
Mike: Yo, Rude, put your dirty socks and smelly pants in the laundry pile!
Rudy: Ah man, leave me alone, can't you see I've got a cold!
(10 minutes later...)
Rudy: See you later Mikey, I'm off to meet Giselle!
Mike (to himself): Man, that dude is a right parabotti!