turncoat

n.背叛者，变节者

noun

1. 叛徒；变节者；叛逆
   a person who leaves one political party, religious group, etc. to join one that has very different views

名词复数形式:turncoats

1. His one-time admirers now accuse him of being a turncoat.
   曾经一度仰慕他的人如今指责他是叛徒。
2. Some of the workers began to see him as a turncoat.
   有些工人开始认为他是一个叛徒。
3. Both suggest that co-operation can be sustained when a short-run game is repeated over and over again, even when the short-run game offers strong temptations to the turncoat.
   上述两种方法都表明，当一个短游戏不断重复的时候，合作是可以持续的，就算这个短游戏能为背叛者提供强大的诱惑。