a. [ See Treacher. ] Like a traitor; involving treachery; violating allegiance or faith pledged; traitorous to the state or sovereign; perfidious in private life; betraying a trust; faithless. [ 1913 Webster ]
Loyal father of a treacherous son. Shak. [ 1913 Webster ]
The treacherous smile, a mask for secret hate. Cowper. [ 1913 Webster ]
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