Abbey
Middle English: from Old French abbeie, from medieval Latin abbatia ‘abbacy’, from abbas, abbat- (see abbot).
wiktionary
From A.D. 1250 in Middle English abbey, abbeye(“convent headed by an abbot”) (compare archaic English abbaye), itself borrowed from Old French abaïe, abbaïe, abeïe, abbeïe (Modern French abbaye) from Late Latin or Ecclesiastical Latin abbātia, from Classical Latin abbās(“abbot”). Doublet of abbacy. See abbot.
etymonline
abbey (n.)
mid-13c., "monastery or convent devoted to religion and celibacy, headed by an abbot or abbess," from Anglo-French abbeie, Old French abaïe (Modern French abbaye), from Late Latin abbatia, from abbas (genitive abbatis); see abbot. At the dissolution of the monasteries, the name often was kept by abbey churches (as in Westminster Abbey) or estate houses that formerly were abbey residences.
