1N-COUNT 背叛(信仰)者;背信弃义者 If you call someone a traitor, you mean that they have betrayed beliefs that they used to hold, or that their friends hold, by their words or actions. 背叛(信仰)者;背信弃义者 [disapproval]
Some say he's a traitor to the working class. [+ to]
2N-COUNT (尤指战时的)卖国贼,叛徒 If someone is a traitor, they betray their country or a group of which they are a member by helping its enemies, especially during time of war. (尤指战时的)卖国贼,叛徒
...rumours that there were traitors among us who were sending messages to the enemy.