The Collaborative International Dictionary of English v.0.48:

Withdrawing-room \With*draw"ing-room`\, n. [See Withdraw, and
   cf. Drawing-room.]
   A room for retirement from another room, as from a dining
   room; a drawing-room.
   [1913 Webster]

         A door in the middle leading to a parlor and
         withdrawing-room.                        --Sir W.
                                                  Scott.
   [1913 Webster]