The hungry ghost seeks validity outside of themselves. Someone pining for an indifferent ex is a hungry ghost. Someone who arrives alone at 6:30 on Saturday night to a pub is probably a hungry ghost. Obsessive checking of mobile phones, chat sites or networks are clear signs that one is a hungry ghost.
The best thing to do is just stay home and ride it out. Read a book. Find some good clean fun.
Dumped: I'm a hungry ghost, man.
Mate: What'd ya do last night?
HG: Urg. I hungry ghosted around The Oxford for a few hours, then walked home past her house, and HIS car was there...
Mate: Why'd you call man?! It's just rampant hungry ghostery.
Also the act of telling about hungry ghost.
Stand there with both arms raised above the head (like a Boo Ghost), move the fingers around, while making licking and eating faces.
While saying "Damn dude, I was like all hungry ghost on her!"