adulteress n.

early 15c., agent noun from obsolete verb adulter "commit adultery; adulterate, make impure, pollute" (late 14c.), from Latin adulterare "to corrupt" (see adulteration). The earlier form in Middle English was avouter (c. 1300), avoutrer (late 14c.), "person (usually a man) guilty of adultery," from Old French avoutrier, from the Latin verb, or from Latin adulter "adulterer, seducer," noun use of an adjective.

fem. suffix, from French -esse, from Late Latin -issa, from Greek -issa (cognate with Old English fem. agent suffix -icge); rare in classical Greek but more common later, in diakonissa "deaconess" and other Church terms picked up by Latin.