turn against有背叛的意思吗

有！
turn against
(使)变成和...敌对

也就是背叛了

（使）开始讨厌；（使）反目
应该不是一个意思！

turn against
(使)转为反对; (使)变成和…敌对
Those who were once for him have turned against him.
那些原来支持他的人现在倒过来反对他了。

背叛；反对；翻脸；疏远；敌对