Late Middle English; earliest use found in The Wycliffite Bible (early version). From (i) Anglo-Norman avoutere, avouteire, avouter, avoutour, advouter, advoutoure and Middle French avoutre, also adultere, also adultre, used as both noun and adjective<br>late Middle English; earliest use found in The Wycliffite Bible (early version). From Middle French avoultrer, advoultrer, also Middle French adulterer to commit adultery, to alter, corrupt, falsify and its etymon classical Latin adulterāre to commit adultery (with), to defile by adultery, to mix (a substance) with another, to impair the purity or strength of, to counterfeit, to falsify or tamper with, to corrupt, debase from ad to + alter another.