A·dŭl'ter·y, n.

n. [Lat. adulterium, Fr. adultere.] 1. Violation of the marriage bed; the unfaithfulness of any married person to the marriage bed; the voluntary sexual intercourse of a married person with one of the opposite sex. ☞ It may be committed between two married persons, or between two persons, only one of whom is married; in the latter case it would be single adultery; in the former, double.

2. Adulteration, corruption. [Obs.]
3. (Script.) Lewdness or unchastity of thought as well as act, as forbidden in the seventh commandment.
4. (Old Law.) The fine and penalty imposed for the offense of adultery.
5. (Eccl.) The intrusion of a person into a bishopric during the life of a bishop. Encyc. Brit.
6. Injury; degradation; ruin. [Obs.]

You might wrest the caduceus out of my hand to the adultery and spoil of nature. B. Jonson.