The Collaborative International Dictionary of English v.0.48:

Panel \Pan"el\, n. [Orig., a little piece; OF. panel, pannel, F.
   panneau, dim. of pan skirt, lappet, part or piece of a wall,
   side. See 2d Pane.]
   1. (Arch.) A sunken compartment with raised margins, molded
      or otherwise, as in ceilings, wainscotings, etc.
      [1913 Webster]

   2. (Law)
      (a) A piece of parchment or a schedule, containing the
          names of persons summoned as jurors by the sheriff;
          hence, more generally, the whole group of persons
          summoned on a particular day, from whom a jury is to
          be selected; also, the jury selected from that group.
          --Blackstone.
      (b) (Scots Law) A prisoner arraigned for trial at the bar
          of a criminal court. --Burrill.
          [1913 Webster]

   3. Hence: Any group of persons selected to judge a contest,
      conduct a discussion, serve as advisers, or participate in
      any group activity in which they will provide information
      or make judgments.
      [PJC]

   4. Formerly, a piece of cloth serving as a saddle; hence, a
      soft pad beneath a saddletree to prevent chafing.
      [1913 Webster]

   5. (Joinery) A board having its edges inserted in the groove
      of a surrounding frame; as, the panel of a door.
      [1913 Webster]

   6. (Masonry) One of the faces of a hewn stone. --Gwilt.
      [1913 Webster]

   7. (Painting) A slab or plank of wood upon which, instead of
      canvas, a picture is painted.
      [1913 Webster]

   8. (Mining)
      (a) A heap of dressed ore.
      (b) One of the districts divided by pillars of extra size,
          into which a mine is laid off in one system of
          extracting coal.
          [1913 Webster]

   9. (Dressmaking) A plain strip or band, as of velvet or
      plush, placed at intervals lengthwise on the skirt of a
      dress, for ornament.
      [1913 Webster]

   10. A portion of a framed structure between adjacent posts or
       struts, as in a bridge truss.
       [1913 Webster]

   11. (A["e]ronautics) A segment of an a["e]roplane wing. In a
       biplane the outer panel extends from the wing tip to the
       next row of posts, and is trussed by oblique stay wires.
       [Webster 1913 Suppl.]

   Panel game, a method of stealing money in a panel house.

   Panel house, a house of prostitution in which the rooms
      have secret entrances to facilitate theft from customers
      by accomplices of the inmates.

   Panel saw, handsaw with fine teeth, -- used for cutting out
      panels, etc.

   Panel thief, one who robs in a panel house.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Panel \Pan"el\, v. t. [imp. & p. p. Paneledor Panelled; p.
   pr. & vb. n. Paneling or Panelling.]
   To form in or with panels; as, to panel a wainscot.
   [1913 Webster]

   Paneled back (Arch.), the paneled work covering the window
      back. See Window back.
      [1913 Webster]

WordNet (r) 3.0 (2006):

panel
    n 1: sheet that forms a distinct (usually flat and rectangular)
         section or component of something
    2: a committee appointed to judge a competition [syn: jury,
       panel]
    3: (law) a group of people summoned for jury service (from whom
       a jury will be chosen) [syn: panel, venire]
    4: a group of people gathered for a special purpose as to plan
       or discuss an issue or judge a contest etc
    5: a soft pad placed under a saddle
    6: a piece of cloth that is generally triangular or tapering;
       used in making garments or umbrellas or sails [syn: gore,
       panel]
    7: (computer science) a small temporary window in a graphical
       user interface that appears in order to request information
       from the user; after the information has been provided the
       user dismisses the box with `okay' or `cancel' [syn: dialog
       box, panel]
    8: electrical device consisting of a flat insulated surface that
       contains switches and dials and meters for controlling other
       electrical devices; "he checked the instrument panel";
       "suddenly the board lit up like a Christmas tree" [syn:
       control panel, instrument panel, control board,
       board, panel]
    v 1: decorate with panels; "panel the walls with wood"
    2: select from a list; "empanel prospective jurors" [syn:
       empanel, impanel, panel]

Moby Thesaurus II by Grady Ward, 1.0:

153 Moby Thesaurus words for "panel":
   accessory, assemblee, assembly, assignation, at home, ball,
   barrier, blue-ribbon jury, brattice, brawl, buffer, buffer state,
   bulkhead, bumper, caucus, cloison, coat, coating, collision mat,
   collop, colloquium, commission, committee, conclave, concourse,
   congregation, congress, conventicle, convention, convocation,
   council, country, covering, cushion, cut, dance, date, deal,
   defendant, diaphragm, diet, discussion group, disk, dissepiment,
   divide, dividing line, dividing wall, division, eisteddfod,
   fence off, fender, festivity, fete, feuille, film, flap, foil,
   fold, forgathering, forum, gathering, get-together, grand jury,
   housewarming, hung jury, impanel, impanel a jury, inquest,
   interseptum, jury, jury list, jury of inquest, jury of matrons,
   jury panel, lamella, lamina, laminated glass, laminated wood, lap,
   leaf, levee, litigant, litigationist, litigator, mat, meet,
   meeting, membrane, midriff, midsection, open forum, pad, pane,
   paries, parties litigant, partition, party, party wall, patina,
   peel, pellicle, petit jury, plaintiff, plait, plank, plate,
   plating, plenum, ply, plywood, police jury, prom, property line,
   quorum, rally, rasher, reception, rendezvous, round table,
   safety glass, scum, seance, separate, separation, septulum, septum,
   session, sessions, set apart, sheet, shindig, shock pad, sit-in,
   sitting, skin, slab, slat, slice, soiree, special jury, suitor,
   symposium, synod, table, tablet, trial jury, turnout, veneer,
   venire, wafer, wall, wall off, witness



Bouvier's Law Dictionary, Revised 6th Ed (1856):

PANEL, practice. A schedule or roll containing the names of jurors, summoned
by virtue of a writ of venire facias, and annexed to the writ. It is
returned into the court whence the venire issued. Co. Litt. 158, b.