treason treason /ˈtriːzən/

noun

1. () A crime that undermines the offender's government  ( high treason , lese majesty , treason )
   a crime that undermines the offender's government
     The traitor was accused of committing acts of treason against the nation.
   The traitor was accused of committing acts of treason against the nation.
   
   
2. An act of deliberate betrayal  ( perfidy , treachery , treason , betrayal )
   an act of deliberate betrayal
   
3. Disloyalty by virtue of subversive behavior  ( subversiveness , traitorousness , treason )
   disloyalty by virtue of subversive behavior