1. He was cruel, treacherous and unscrupulous.
    他残忍、奸诈、不择手段。

2. My memory is treacherous.
    我的记忆不可靠了。

1. 背叛的：trddition 传统 | treacherous 背叛的 | treacherously 背叛地

2. 叛逆的：jagged:不平的 | treacherous:叛逆的 | shoals:浅滩

3.

3. 阴险的、狡诈的、有阴谋的、有诡计的：appropriate 恰当的、合适的、拨款 | treacherous 阴险的、狡诈的、有阴谋的、有诡计的 | expel 开除学籍、赶走

4. 阴险的,危险的：odoriferous 有香味的,芳香的 | treacherous 阴险的,危险的 | lecherous 好色的

1. 奸诈的;背信弃义的;不可信任的
    If you describe someone as treacherous, you mean that they are likely to betray you and cannot be trusted.

    e.g. He publicly left the party and denounced its treacherous leaders...
           他公开脱离该党，并谴责该党领袖背信弃义。
    e.g. The President spoke of the treacherous intentions of the enemy.
           总统谈及了敌人的奸诈用心。

2. 危险的;变化无常的
    If you say that something is treacherous, you mean that it is very dangerous and unpredictable.

    e.g. The current of the river is fast flowing and treacherous...
           这条河水流湍急，变幻莫测。
    e.g. They made the treacherous journey across stormy seas in rotten boats.
           他们乘着破旧的小船穿越风大浪急的海面，完成了这次危险之旅。

1. tending to betray
    especially having a treacherous character as attributed to the Carthaginians by the Romans

    e.g. Punic faith
           the perfidious Judas
           the fiercest and most treacherous of foes
           treacherous intrigues

    Synonym: punicperfidious

2. dangerously unstable and unpredictable

    e.g. treacherous winding roads
           an unreliable trestle

    Synonym: unreliable