The Collaborative International Dictionary of English v.0.48:

Corps \Corps\ (k[=o]r, pl. k[=o]rz), n. sing. & pl. [F., fr. L.
   corpus body. See Corpse.]
   1. The human body, whether living or dead. [Obs.] See
      Corpse, 1.
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            By what craft in my corps, it cometh [commences] and
            where.                                --Piers
                                                  Plowman.
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   2. A body of men; esp., an organized division of the military
      establishment; as, the marine corps; the corps of
      topographical engineers; specifically, an army corps.
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            A corps operating with an army should consist of
            three divisions of the line, a brigade of artillery,
            and a regiment of cavalry.            --Gen. Upton
                                                  (U. S.
                                                  Tactics. )
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   3. A body or code of laws. [Obs.]
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            The whole corps of the law.           --Bacon.
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   4. (Eccl.) The land with which a prebend or other
      ecclesiastical office is endowed. [Obs.]
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            The prebendaries over and above their reserved rents
            have a corps.                         --Bacon.
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   5. [Ger.] In some countries of Europe, a form of students'
      social society binding the members to strict adherence to
      certain student customs and its code of honor; -- Ger.
      spelling usually korps.
      [Webster 1913 Suppl.]

   Army corps, or (French) Corps d'arm['e]e (k[-o]r`
      d[aum]r`m[asl]"), a body containing two or more divisions
      of a large army, organized as a complete army in itself.


   Corps de logis (k[-o]r` de l[-o]`zh[-e]") [F., body of the
      house], the principal mass of a building, considered apart
      from its wings.

   Corps diplomatique (k?r d?`pl?`m?-t?k") [F., diplomatic
      body], the body of ministers or envoys accredited to a
      government.
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WordNet (r) 3.0 (2006):

army corps
    n 1: an army unit usually consisting of two or more divisions
         and their support [syn: corps, army corps]