traitor

1. N-COUNT 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. 背叛者[表不滿]

Some say he's a traitor to the peace movement. 一些人說他是和平運動的背叛者。

2. N-COUNT If someone is a traitor, they betray their country, friends, or a group of which they are a member by helping its enemies, especially during time of war. (尤指戰爭期間的) 賣國賊; 叛徒

...rumours that there were traitors among us who were sending messages to the enemy. …謠言說我們中有正給敵人送信的叛徒。