Source : Webster's Revised Unabridged Dictionary (1913)

Book \Book\, v. t. [imp. & p. p. {Booked}; p. pr. & vb. n.
   {Booking}.]
   1. To enter, write, or register in a book or list.

            Let it be booked with the rest of this day's deeds.
                                                  --Shak.

   2. To enter the name of (any one) in a book for the purpose
      of securing a passage, conveyance, or seat; as, to be
      booked for Southampton; to book a seat in a theater.

   3. To mark out for; to destine or assign for; as, he is
      booked for the valedictory. [Colloq.]

            Here I am booked for three days more in Paris.
                                                  --Charles
                                                  Reade.

Booked \Booked\, a.
   1. Registered.

   2. On the way; destined. [Colloq.]

Source : WordNet®

booked
     adj : reserved in advance [syn: {engaged}, {set-aside(p)}]