Meaning of treacherous

(adj) dangerously unstable and unpredictable; "treacherous winding roads"; "an unreliable trestle"

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"