Source : Webster's Revised Unabridged Dictionary (1913)

Shoulder \Shoul"der\, n. [OE. shulder, shuldre, schutder, AS.
   sculdor; akin to D. schoulder, G. schulter, OHG. scultarra,
   Dan. skulder, Sw. skuldra.]
   1. (Anat.) The joint, or the region of the joint, by which
      the fore limb is connected with the body or with the
      shoulder girdle; the projection formed by the bones and
      muscles about that joint.

   2. The flesh and muscles connected with the shoulder joint;
      the upper part of the back; that part of the human frame
      on which it is most easy to carry a heavy burden; -- often
      used in the plural.

            Then by main force pulled up, and on his shoulders
            bore The gates of Azza.               --Milton.

            Adown her shoulders fell her length of hair.
                                                  --Dryden.

   3. Fig.: That which supports or sustains; support.

            In thy shoulder do I build my seat.   --Shak.

   4. That which resembles a human shoulder, as any protuberance
      or projection from the body of a thing.

            The north western shoulder of the mountain. --Sir W.
                                                  Scott.

   5. The upper joint of the fore leg and adjacent parts of an
      animal, dressed for market; as, a shoulder of mutton.

   6. (Fort.) The angle of a bastion included between the face
      and flank. See Illust. of {Bastion}.

   7. An abrupt projection which forms an abutment on an object,
      or limits motion, etc., as the projection around a tenon
      at the end of a piece of timber, the part of the top of a
      type which projects beyond the base of the raised
      character, etc.

   {Shoulder belt}, a belt that passes across the shoulder.

   {Shoulder blade} (Anat.), the flat bone of the shoulder, to
      which the humerus is articulated; the scapula.

   {Shoulder block} (Naut.), a block with a projection, or
      shoulder, near the upper end, so that it can rest against
      a spar without jamming the rope.

   {Shoulder clapper}, one who claps another on the shoulder, or
      who uses great familiarity. [Obs.] --Shak.

   {Shoulder girdle}. (Anat.) See {Pectoral girdle}, under
      {Pectoral}.

   {Shoulder knot}, an ornamental knot of ribbon or lace worn on
      the shoulder; a kind of epaulet or braided ornament worn
      as part of a military uniform.

   {Shoulder-of-mutton sail} (Naut.), a triangular sail carried
      on a boat's mast; -- so called from its shape.

   {Shoulder slip}, dislocation of the shoulder, or of the
      humerous. --Swift.

   {Shoulder strap}, a strap worn on or over the shoulder.
      Specifically (Mil. & Naval), a narrow strap worn on the
      shoulder of a commissioned officer, indicating, by a
      suitable device, the rank he holds in the service. See
      Illust. in App.

Source : WordNet®

shoulder girdle
     n : the bony arch formed by the collarbones and shoulder blades
         in humans [syn: {pectoral arch}]