Source : Webster's Revised Unabridged Dictionary (1913)

Disloyal \Dis*loy"al\, a. [Pref. dis- + loyal: cf. OF. desloial,
   desleal, F. d['e]loyal. See {Loyal}.]
   Not loyal; not true to a sovereign or lawful superior, or to
   the government under which one lives; false where allegiance
   is due; faithless; as, a subject disloyal to the king; a
   husband disloyal to his wife.

         Without a thought disloyal.              --Mrs.
                                                  Browning.

   Syn: Disobedient; faithless; untrue; treacherous; perfidious;
        dishonest; inconstant; disaffected.

Source : WordNet®

disloyal
     adj 1: showing lack of love for your country [syn: {unpatriotic}]
            [ant: {patriotic}]
     2: deserting your allegiance or duty to leader or cause or
        principle; "disloyal aides revealed his indiscretions to
        the papers" [ant: {loyal}]