The Collaborative International Dictionary of English v.0.48:

Side \Side\ (s[imac]d), n. [AS. s[imac]de; akin to D. zijde, G.
   seite, OHG. s[imac]ta, Icel. s[imac]?a, Dan. side, Sw. sida;
   cf. AS. s[imac]d large, spacious, Icel. s[imac]?r long,
   hanging.]
   1. The margin, edge, verge, or border of a surface;
      especially (when the thing spoken of is somewhat oblong in
      shape), one of the longer edges as distinguished from the
      shorter edges, called ends; a bounding line of a
      geometrical figure; as, the side of a field, of a square
      or triangle, of a river, of a road, etc.
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   3. Any outer portion of a thing considered apart from, and
      yet in relation to, the rest; as, the upper side of a
      sphere; also, any part or position viewed as opposite to
      or contrasted with another; as, this or that side.
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            Looking round on every side beheld
            A pathless desert.                    --Milton.
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   4.
      (a) One of the halves of the body, of an animals or man,
          on either side of the mesial plane; or that which
          pertains to such a half; as, a side of beef; a side of
          sole leather.
      (b) The right or left part of the wall or trunk of the
          body; as, a pain in the side.
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                One of the soldiers with a spear pierced his
                side.                             --John xix.
                                                  34.
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   5. A slope or declivity, as of a hill, considered as opposed
      to another slope over the ridge.
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            Along the side of yon small hill.     --Milton.
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   6. The position of a person or party regarded as opposed to
      another person or party, whether as a rival or a foe; a
      body of advocates or partisans; a party; hence, the
      interest or cause which one maintains against another; a
      doctrine or view opposed to another.
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            God on our side, doubt not of victory. --Shak.
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            We have not always been of the . . . same side in
            politics.                             --Landor.
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            Sets the passions on the side of truth. --Pope.
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   7. A line of descent traced through one parent as
      distinguished from that traced through another.
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            To sit upon thy father David's throne,
            By mother's side thy father.          --Milton.
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   8. Fig.: Aspect or part regarded as contrasted with some
      other; as, the bright side of poverty.
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   By the side of, close at hand; near to.

   Exterior side. (Fort.) See Exterior, and Illust. of
      Ravelin.

   Interior side (Fort.), the line drawn from the center of
      one bastion to that of the next, or the line curtain
      produced to the two oblique radii in front. --H. L. Scott.

   Side by side, close together and abreast; in company or
      along with.

   To choose sides, to select those who shall compete, as in a
      game, on either side.

   To take sides, to attach one's self to, or give assistance
      to, one of two opposing sides or parties.
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