If someone is sold a pup, they buy or accept something that is not as good as they thought it would be. It's the car you want at the price you want to pay. But can you trust the seller, or will you be sold a pup? The pictures were published in good faith but the newspaper discovered two days later that they had been sold a pup. Note: A pup is a puppy or young dog, and is probably being contrasted with an animal that is older and does not need to be trained before being put to work.