The Collaborative International Dictionary of English v.0.48:

Board \Board\, v. t. [imp. & p. p. Boarded; p. pr. & vb. n.
   Boarding.]
   1. To cover with boards or boarding; as, to board a house.
      "The boarded hovel." --Cowper.
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   2. [Cf. Board to accost, and see Board, n.] To go on
      board of, or enter, as a ship, whether in a hostile or a
      friendly way.
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            You board an enemy to capture her, and a stranger to
            receive news or make a communication. --Totten.
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   3. To enter, as a railway car. [Colloq. U. S.]
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   4. To furnish with regular meals, or with meals and lodgings,
      for compensation; to supply with daily meals.
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   5. To place at board, for compensation; as, to board one's
      horse at a livery stable.
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The Collaborative International Dictionary of English v.0.48:

Boarding \Board"ing\, n.
   1. (Naut.) The act of entering a ship, whether with a hostile
      or a friendly purpose.
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            Both slain at one time, as they attempted the
            boarding of a frigate.                --Sir F.
                                                  Drake.
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   2. The act of covering with boards; also, boards,
      collectively; or a covering made of boards.
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   3. The act of supplying, or the state of being supplied, with
      regular or specified meals, or with meals and lodgings,
      for pay.
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   Boarding house, a house in which boarders are kept.

   Boarding nettings (Naut.), a strong network of cords or
      ropes erected at the side of a ship to prevent an enemy
      from boarding it.

   Boarding pike (Naut.), a pike used by sailors in boarding a
      vessel, or in repelling an attempt to board it. --Totten.

   Boarding school, a school in which pupils receive board and
      lodging as well as instruction.
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WordNet (r) 3.0 (2006):

boarding
    n 1: the act of passengers and crew getting aboard a ship or
         aircraft [syn: boarding, embarkation, embarkment]
         [ant: debarkation, disembarkation, disembarkment]
    2: a structure of boards