unfaithful

unfaithful
    adj 1: not true to duty or obligation or promises; "an
           unfaithful lover" [ant: {faithful}]
    2: having sexual relations with someone other than your husband
       or wife, or your boyfriend or girlfriend; "her husband was
       unfaithful" [ant: {faithful}]
    3: having the character of, or characteristic of, a traitor;
       "the faithless Benedict Arnold"; "a lying traitorous
       insurrectionist" [syn: {faithless}, {traitorous},
       {unfaithful}, {treasonable}, {treasonous}]
    4: not trustworthy; "an unfaithful reproduction"
    

Unfaithful \Un*faith"ful\, a.
   1. Not faithful; not observant of promises, vows, allegiance,
      or duty; violating trust or confidence; treacherous;
      perfidious; as, an unfaithful subject; an unfaithful agent
      or servant.
      [1913 Webster]

            My feet, through wine, unfaithful to their weight.
                                                  --Pope.
      [1913 Webster]

            His honor rooted in dishonor stood,
            And faith unfaithful kept him falsely true.
                                                  --Tennyson.
      [1913 Webster]

   2. Not possessing faith; infidel. [R.] --Milton.
      [1913 Webster] -- {Un*faith"ful*ly}, adv. --
      {Un*faith"ful*ness}, n.
      [1913 Webster]
    

28 Moby Thesaurus words for "unfaithful":
      derelict, disaffected, disloyal, disregardful, faithless, false,
      fickle, inattentive, inconstant, inobservant, negligent,
      nonadherent, noncompliant, nonconforming, nonobservant,
      not true to, of bad faith, perfidious, recreant, traitorous,
      treacherous, trothless, uncompliant, unconforming, unloyal,
      unobservant, unsteadfast, untrue