The Collaborative International Dictionary of English v.0.48:

Girdle \Gir"dle\, n. [OE. gurdel, girdel, AS. gyrdel, fr.
   gyrdan; akin to D. gordel, G. g["u]rtel, Icel. gyr?ill. See
   Gird, v. t., to encircle, and cf. Girth, n.]
   [1913 Webster]
   1. That which girds, encircles, or incloses; a circumference;
      a belt; esp., a belt, sash, or article of dress encircling
      the body usually at the waist; a cestus.
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            Within the girdle of these walls.     --Shak.
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            Their breasts girded with golden girdles. --Rev. xv.
                                                  6.
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   2. The zodiac; also, the equator. [Poetic] --Bacon.
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            From the world's girdle to the frozen pole.
                                                  --Cowper.
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            That gems the starry girdle of the year. --Campbell.
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   3. (Jewelry) The line ofgreatest circumference of a
      brilliant-cut diamond, at which it is grasped by the
      setting. See Illust. of Brilliant. --Knight.
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   4. (Mining) A thin bed or stratum of stone. --Raymond.
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   5. (Zool.) The clitellus of an earthworm.
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   Girdle bone (Anat.), the sphenethmoid. See under
      Sphenethmoid.

   Girdle wheel, a spinning wheel.

   Sea girdle (Zool.), a ctenophore. See Venus's girdle,
      under Venus.

   Shoulder, Pectoral, & Pelvic, girdle. (Anat.) See
      under Pectoral, and Pelvic.

   To have under the girdle, to have bound to one, that is, in
      subjection.
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The Collaborative International Dictionary of English v.0.48:

Pectoral \Pec"to*ral\, n. [L. pectorale a breastplate, neut. of
   pectoralis.]
   1. A covering or protecting for the breast.
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   2. (Eccl.)
      (a) A breastplate, esp. that worn by the Jewish high
          person.
      (b) A clasp or a cross worn on the breast.
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   3. A medicine for diseases of the chest organs, especially
      the lungs.
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The Collaborative International Dictionary of English v.0.48:

Pectoral \Pec"to*ral\ (p[e^]k"t[-o]*ral), a. [L. pectoralis, fr.
   pectus, -oris the breast; cf. F. pectoral.]
   1. Of or pertaining to the breast, or chest; as, the pectoral
      muscles.
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   2. Relating to, or good for, diseases of the chest or lungs;
      as, a pectoral remedy.
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   3. (Zool.) Having the breast conspicuously colored; as, the
      pectoral sandpiper.
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   Pectoral arch, or Pectoral girdle (Anat.), the two or
      more bony or cartilaginous pieces of the vertebrate
      skeleton to which the fore limbs are articulated; the
      shoulder girdle. In man it consists of two bones, the
      scapula and clavicle, on each side.

   Pectoral cross (Eccl.), a cross worn on the breast by
      bishops and abbots, and sometimes also by canons.

   Pectoral fins, or Pectorals (Zool.), fins situated on the
      sides, behind the gills. See Illust. under Fin.

   Pectoral rail. (Zool.) See Land rail
      (b) under Land.

   Pectoral sandpiper (Zool.), the jacksnipe
      (b) .
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WordNet (r) 3.0 (2006):

pectoral
    adj 1: of or relating to the chest or thorax; "pectoral organ"
           [syn: pectoral, thoracic]
    n 1: either of two large muscles of the chest [syn: pectoral,
         pectoral muscle, pectoralis, musculus pectoralis,
         pecs]
    2: an adornment worn on the chest or breast [syn: pectoral,
       pectoral medallion]