n. a nun in charge of a priory; an abbess or mother superior
the GNU version of the Collaborative International Dictionary of English
n. A lady superior of a priory of nuns, and next in dignity to an abbess.
The Century Dictionary and Cyclopedia
n. A female prior, having charge of a religious house; a woman who is the coadjutor of and next in rank to an abbess.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
n. the superior of a group of nuns
Word Usage
"The term prioress is properly applied only to a superioress in a convent which has the papal approbation and whose members make solemn profession, that is, to convents which belong to an order in the strict sense of the word."