The idiom "fell off a truck" means that something was obtained illegally or through questionable means. It is often used to describe goods that are being sold at a suspiciously low price or without proper documentation.
For example, if someone offers to sell you a brand new iPhone for a fraction of its retail price and cannot provide a receipt or proof of purchase, you might suspect that the phone "fell off a truck" and was stolen or obtained illegally.
This idiom can also be used in a more humorous or sarcastic way to describe something that is obviously fake or counterfeit. For instance, if someone shows you a knockoff designer handbag and claims it is authentic, you might say, "Oh, I'm sure that fell off a truck somewhere."
Overall, the idiom "fell off a truck" is a way to express suspicion or skepticism about the origin or legitimacy of something.
• I found this watch on the ground. It must have fallen off a truck.
• My friend has a new TV, but I suspect it fell off a truck.
• The police found a large quantity of stolen goods that had fallen off a truck during a high-speed chase.
• The politician denied any wrongdoing, claiming that the cash found in his possession had fallen off a truck.
• We can't sell these goods because they fell off a truck and we don't know if they were stolen or not.
• The company faced a scandal when it was revealed that their products were illegally obtained and fell off a truck.