What is Advoutry?

Legal Definition
In old English law. Adultery between parties bath of whom were married. Hunter v. In S., 1 Pin. (Wist) 91, 39 Am. Dec. 277. Or the offence by an adulteress of continuing to live with the man with whom she committed the adultery. Cowell; Termes de la Ley. Sometimes spelled "advowtry."
-- Black's Law Dictionary
Legal Definition
-- Ballentine's Law Dictionary