Boomba is a game featured in iParty with Victorious.
Each player gets three oranges and turns away from the other. They then try to throw the orange onto the other's backs. The winner, as in the person to hit the other with an orange first, shouts, "BOOMBA!". The game was taught to Sam Puckett by her mother, Pam Puckett.
In the episode, Sam surprisingly hits Freddie on the back with an orange while his back is turned, winning the game. Freddie then says to Carly, who is on the computer, "See if you can look up if oranges can break a spine, CAUSE I THINK THEY CAN!!!"
A few minutes later, while Freddie is gushing over a photograph of the girl Carly's boyfriend Steven might be cheating on her with, Carly picks up the orange and chucks it at Freddie. When he gets hit, he falls out of his chair.