The Collaborative International Dictionary of English v.0.48:

Right-about \Right"-a*bout`\, n. [Right, adv. + about, adv.]
   A turning directly about by the right, so as to face in the
   opposite direction; also, the quarter directly opposite; as,
   to turn to the right-about.
   [1913 Webster]

   To send to the right-about, to cause to turn toward the
      opposite point or quarter; -- hence, of troops, to cause
      to turn and retreat. [Colloq.] --Sir W. Scott.
      [1913 Webster]