What is blackmail? How to use in English

The word "blackmail" has its origin in Scottish history. In the 14th century, the Blackmail was a type of unpaid labor or service owed by a vassal to their lord. The lord would demand this labor in exchange for protection or land tenure. Over time, the term "blackmail" evolved to refer to the act of extorting money or favors by threat or coercion. In the 16th century, the term gained a new connotation in England, where it referred to the practice of exacting money from Scottish tenants by threat of violence or the destruction of their property. This practice was known as "black rent" or "black mail," as it was often exacted by Scottish nobles who wore black armor. Today, the term "blackmail" is used more broadly to describe any form of extortion or coercion, where one party threatens to disclose secret information or commit an act of violence if their demands are not met.