/ˈtreɪtər/
trai·tor
BrE /ˈtreɪtə(r)/
NAmE /ˈtreɪtər/
~ (to sb/sth)
a person who gives away secrets about their friends, their country, etc.
He was seen as a traitor to the socialist cause.
She denied that she had turned traitor (= become a traitor ).