The Collaborative International Dictionary of English v.0.48:

Atone \A*tone"\ ([.a]*t[=o]n"), v. i. [imp. & p. p. Atoned; p.
   pr. & vb. n. Atoning.] [From at one,, i. e., to be, or
   cause to be, at one. See At one.]
   1. To agree; to be in accordance; to accord. [Obs.]
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            He and Aufidius can no more atone
            Than violentest contrariety.          --Shak.
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   2. To stand as an equivalent; to make reparation,
      compensation, or amends, for an offense or a crime.
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            The murderer fell, and blood atoned for blood.
                                                  --Pope.
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            The ministry not atoning for their former conduct by
            any wise or popular measure.          --Junius.
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