Late Middle English; earliest use found in John Lydgate (c1370–c1449), poet and prior of Hatfield Regis. Originally from Middle French prestresse from Old French prestre + -esse. In later use apparently re-formed from priest + -tress, unless simply showing a typographical error for priestess.
Definition of priestress in US English:
priestress
noun
US
Priestess.
Origin
Late Middle English; earliest use found in John Lydgate (c1370–c1449), poet and prior of Hatfield Regis. Originally from Middle French prestresse from Old French prestre + -esse. In later use apparently re-formed from priest + -tress, unless simply showing a typographical error for priestess.