/ Thesaurus / G Synonyms of gregory xiii Find synonyms for: Noun1. Gregory, Gregory XIII, Ugo Buoncompagniusage: the pope who sponsored the introduction of the modern calendar (1572-1585)WordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: blanch Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language