The Collaborative International Dictionary of English v.0.48:

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.
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   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.
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            Then by main force pulled up, and on his shoulders
            bore
            The gates of Azza.                    --Milton.
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            Adown her shoulders fell her length of hair.
                                                  --Dryden.
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   3. Fig.: That which supports or sustains; support.
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            In thy shoulder do I build my seat.   --Shak.
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   4. That which resembles a human shoulder, as any protuberance
      or projection from the body of a thing.
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            The north western shoulder of the mountain. --Sir W.
                                                  Scott.
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   5. The upper joint of the fore leg and adjacent parts of an
      animal, dressed for market; as, a shoulder of mutton.
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   6. (Fort.) The angle of a bastion included between the face
      and flank. See Illust. of Bastion.
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   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.
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   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.
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WordNet (r) 3.0 (2006):

shoulder strap
    n 1: a band that goes over the shoulder and supports a garment
         or bag [syn: strap, shoulder strap]