The Collaborative International Dictionary of English v.0.48:

Doubling \Dou"bling\, n.
   1. The act of one that doubles; a making double;
      reduplication; also, that which is doubled.
      [1913 Webster]

   2. A turning and winding; as, the doubling of a hunted hare;
      shift; trick; artifice. --Dryden.
      [1913 Webster]

   3. (Her.) The lining of the mantle borne about the shield or
      escutcheon.
      [1913 Webster]

   4. The process of redistilling spirits, to improve the
      strength and flavor.
      [1913 Webster]

   5. raising the stakes in a game, such as a card game or
      backgammon, by a factor of 2.

   Syn: double.
        [WordNet 1.5]

   Doubling a cape, promontory, etc. (Naut.), sailing around
      or passing beyond a cape, promontory, etc.
      [1913 Webster]