An intimidating word you use when you want to shake down or scare someone who actually isn't really a friend.
"Call it. Friendo." - A remorseless hitman to a simple store-owner in Texas, from the film "No Country for Old Men." He wants him to call the coin he just flipped. If the store-owner calls it wrong, the hitman will kill him. If he calls it right, he'll let him live. A real friend would just let the guy live regardless.