The Collaborative International Dictionary of English v.0.48:

Retortion \Re*tor"tion\, n. [Cf. F. r['e]torsion. See Retort,
   v. t.]
   1. Act of retorting or throwing back; reflection or turning
      back. [Written also retorsion.]
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            It was, however, necessary to possess some single
            term expressive of this intellectual retortion.
                                                  --Sir W.
                                                  Hamilton.
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   2. (Law) Retaliation. --Wharton.
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