1. In rugby or soccer, to feign a pass, kick, or other maneuver in order to deceive an opponent and get around them. He tried selling me a dummy in a last-ditch effort to score a try and tie the game, but luckily I caught on to what he was up to and managed to bring him to the ground.

2. To sell or pass off something to someone that ultimately proves to be worth nothing or less than promised. I'm sorry, but that's definitely not an authentic Louis Vuitton bag. They sold you a dummy, my friend.