treacherous

I see the wife misused by her husband, I see the treacherous seducer of young women, / I mark the ranklings of jealousy and unrequited love attempted to be hid […]

a treacherous mountain trail

Work on the muskeg resulted in the formation in the first instance, and later in lengths of newly-laid track disappearing without trace into the treacherous bog.

Treacherous fire, bring relief to my torment.

Wet logs make for treacherous footing.

And I said, My leanness, my leanness, woe unto me! The treacherous have dealt treacherously; yea, the treacherous have dealt very treacherously.