trai ‧ tor /ˈtreɪtə $ -ər/ BrE AmE noun [uncountable and countable]
[ Date: 1200-1300 ; Language: Old French ; Origin: traitre , from Latin traditor , from tradere 'to hand over, deliver, betray' , from trans- ( ⇨ ↑ trans- ) + dare 'to give' ]
someone who is not loyal to their country, friends, or beliefs ⇨ treason
traitor to
a traitor to the cause of women’s rights
a politician who turned traitor (=became a traitor) to the government