The U.S. Department of the Treasury's Office of Foreign Assets Control (OFAC) announced that it has added an individual's name to its Specially Designated Nationals and Blocked Persons List (SDN List). This action means the person's property and assets under U.S. jurisdiction are blocked, and U.S. citizens and businesses are not allowed to conduct transactions with them. This decision was made because the individual met certain legal criteria. More information and the full list can be found on OFAC's website.
Simple Explanation
The government has put a person on a special list because they did something wrong, so now people in America can't do business with them. This means their stuff in America is "frozen" and can't be used.