/euh dul"teuh ree/ , n. , pl. adulteries .
voluntary sexual intercourse between a married person and someone other than his or her lawful spouse.
[ 1325-75; ME adulterie adulterium, equiv. to adulter (see ADULTERER) + -ium -IUM; r. ME a ( d ) vouterie avoutrie ad - AD- r. a A- 5 ]