The Collaborative International Dictionary of English v.0.48:

Stowage \Stow"age\, n.
   1. The act or method of stowing; as, the stowage of
      provisions in a vessel.
      [1913 Webster]

   2. Room in which things may be stowed. --Cook.
      [1913 Webster]

            In every vessel is stowage for immense treasures.
                                                  --Addison.
      [1913 Webster]

   3. The state of being stowed, or put away. "To have them in
      safe stowage." --Shak.
      [1913 Webster]

   4. Things stowed or packed. --Beau. & Fl.
      [1913 Webster]

   5. Money paid for stowing goods.
      [1913 Webster]

WordNet (r) 3.0 (2006):

stowage
    n 1: the charge for stowing goods
    2: a room in which things are stored [syn: storeroom, storage
       room, stowage]
    3: the act of packing or storing away [syn: stowage,
       stowing]