It is a combat formation that allows you to throw a flying elbow and karate chop with out your opponent seeing it coming while protecting ur head and body.
Taken from Episode 70 of The Sopranos. Tony kicks his own bodyguards ass to show his guys that he has still got it. He shows them that he is still a tough guy. It's when you show the people in your employment that you can do anything they can AND you can do it better.
A big fat girl that hangs out with a hot girl and cockblocks every guy that tries to talk to the hot girl. This is done because the big fat girl is a hater and is jealous of the hot girl and wants the hot girl to be lonely and miserable just like her.
Joe: I think I could go home with that fine blonde over there but that ugly fat bodyguard girl keeps cockblocking me . I'm getting no where!
Grant: no worries pimpin, I'll take one for the team and hit on the bodyguard. That will distract her so you can make your move.
Someone (usually a friend) who accompanies you to an in-person meeting arranged via Craigslist to provide support in case of anything going wrong (ex: the Craigslist person being dangerous, creepy, or a scammer). The Craigslist Bodyguard can also simply provide moral support or transportation.
Sam: Are you really gonna meet that mechanic from Craigslist? What if he murders you?
John: Don't worry, James is coming as my Craigslist Bodyguard.