treacherous

(s) dangerously unstable and unpredictable
- treacherous winding roads
- an unreliable trestle
unreliable,
(s) tending to betray; especially having a treacherous character as attributed to the Carthaginians by the Romans
- Punic faith
- the perfidious Judas
- the fiercest and most treacherous of foes
- treacherous intrigues
perfidious, punic,

unreliable perfidious punic

treacherously