Source : Webster's Revised Unabridged Dictionary (1913)

Traitorous \Trai"tor*ous\, a. [Cf. F. tra[^i]treux.]
   1. Guilty of treason; treacherous; perfidious; faithless; as,
      a traitorous officer or subject. --Shak.

   2. Consisting in treason; partaking of treason; implying
      breach of allegiance; as, a traitorous scheme. --
      {Trai"tor*ous*ly}, adv. -- {Trai"tor*ous*ness}, n.

Source : WordNet®

traitorously
     adv : in a disloyal and faithless manner; "he behaved
           treacherously"; "his wife played him false" [syn: {faithlessly},
            {treacherously}, {treasonably}, {false}]