Definition of treacherous
1a
: likely to betray trust : unreliable
a treacherous memory
b
: providing insecure footing or support
treacherous quicksand
c
: marked by hidden dangers, hazards, or perils
2
: characterized by or manifesting treachery : perfidious
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Merriam-Webster unabridged
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Time Traveler for treacherous
The first known use of treacherous was in the 14th century
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