The Collaborative International Dictionary of English v.0.48:

Adultery \A*dul"ter*y\, n.; pl. Adulteries. [L. adulterium.
   See Advoutry.]
   1. The unfaithfulness of a married person to the marriage
      bed; sexual intercourse by a married man with another than
      his wife, or voluntary sexual intercourse by a married
      woman with another than her husband.
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   Note: It is adultery on the part of the married wrongdoer.
         The word has also been used to characterize the act of
         an unmarried participator, the other being married. In
         the United States the definition varies with the local
         statutes. Unlawful intercourse between two married
         persons is sometimes called double adultery; between
         a married and an unmarried person, single adultery.
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   2. Adulteration; corruption. [Obs.] --B. Jonson.
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   3. (Script.)
      (a) Lewdness or unchastity of thought as well as act, as
          forbidden by the seventh commandment.
      (b) Faithlessness in religion. --Jer. iii. 9.
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   4. (Old Law) The fine and penalty imposed for the offense of
      adultery.
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   5. (Eccl.) The intrusion of a person into a bishopric during
      the life of the bishop.
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   6. Injury; degradation; ruin. [Obs.]
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            You might wrest the caduceus out of my hand to the
            adultery and spoil of nature.         --B. Jonson.
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