What does abbess mean?
The definition of abbess
Ab”bess, n.
Etym: [OF.abaesse, abeesse, F. abbesse, L. abbatissa, fem. of abbas, abbatis, abbot. See Abbot.]

A female superior or governess of a nunnery, or convent of nuns, having the same authority over the nuns which the abbots have over the monks. See Abbey.