形容词

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.

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.

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