A more thorough explanation:

Definition: Marked money is money that has a special mark on it so that it can be traced back to a specific person or situation. This is often used in criminal investigations to catch people who commit crimes.

Example: If a kidnapper demands a ransom, the police might give them marked money. This means that the money has a special mark on it that only the police know about. If the kidnapper uses the money, the police can trace it back to them and catch them.

Another example: A store owner might mark their money with a special pen to prevent counterfeit bills from being used. If someone tries to use a fake bill, the mark will show up and the store owner will know it's not real.

These examples show how marked money can be used to catch criminals or prevent fraud. It's an important tool for law enforcement and businesses to protect themselves.