1. [n]  the act of assuming or maintaining a seated position; "he read the mystery at one sitting"
2. [n]  the act of assuming a certain position (as for a photograph or portrait); "he wanted his portrait painted but couldn't spare time for the sitting"
3. [n]  a session as of a legislature or court
4. [n]  a meeting of spiritualists; "the seance was held in the medium's parlor"
5. [adj]  (of persons) having the torso erect and legs bent with the body supported on the buttocks; "the seated Madonna"; "the audience remained seated"
6. [adj]  not moving and therefore easy to attack; "a sitting target"

Sitting
An overview of meditation followed by simple, practical techniques derived from Buddhist practice.

more details ...

1. \Sit"ting\, a.
   Being in the state, or the position, of one who, or that
   which, sits.
   

2. \Sit"ting\, n.
   1. The state or act of one who sits; the posture of one who
      occupies a seat.
   2. A seat, or the space occupied by or allotted for a person,
      in a church, theater, etc.; as, the hall has 800 sittings.
   3. The act or time of sitting, as to a portrait painter,
      photographer, etc.
   4. The actual presence or meeting of any body of men in their
      seats, clothed with authority to transact business; a
      session; as, a sitting of the judges of the King's Bench,
      or of a commission.
            The sitting closed in great agitation. --Macaulay.
   5. The time during which one sits while doing something, as
      reading a book, playing a game, etc.
            For the understanding of any one of St. Paul's
            Epistles I read it all through at one sitting.
                                                  --Locke.
   6. A brooding over eggs for hatching, as by fowls.
            The male bird . . . amuses her [the female] with his
            songs during the whole time of her sitting.
                                                  --Addison.
   {Sitting room}, an apartment where the members of a family
      usually sit, as distinguished from a drawing-room, parlor,
      chamber, or kitchen.
   

the attitude generally assumed in Palestine by those who were engaged in any kind of work. "The carpenter saws, planes, and hews with his hand-adze, sitting on the ground or upon the plank he is planning. The washerwoman sits by the tub; and, in a word, no one stands when it is possible to sit. Shopkeepers always sit, and Levi sitting at the receipt of custom (Matt. 9:9) is the exact way to state the case.", Thomson, Land and Book.