Traitor

A traitor is someone who does something really, really bad to the people or country that they are supposed to be loyal to. It's like if you had a secret club with your friends and one of your friends told all the secret stuff to someone else who wasn't in the club. They broke the rules and didn't stay loyal to the club, and that's what a traitor does to their country. They might tell secrets or help someone else who wants to do bad things to the country. It's super bad and people get really upset when they find out someone is a traitor.