treacherous

1. ADJ If you describe someone as treacherous, you mean that they are likely to betray you and cannot be trusted. 背信弃义的[表不满]

He publicly left the party and denounced its treacherous leaders. 他公开脱离了该党，并遣责党内那些背信弃义的领导人们。

2. ADJ If you say that something is treacherous, you mean that it is very dangerous and unpredictable. 危险的; 变化莫测的

The current of the river is fast flowing and treacherous. 河水的水流湍急而且变化莫测。