1. (Roman Catholic Church) a church father known for his constant fight against perceived heresies; a saint and Doctor of the Church (329-391) Noun
2. Italian pope from 1831 to 1846; conservative in politics and theology; worked to propagate Catholicism in England and the United States (1765-1846) Noun
3. The pope who sponsored the introduction of the modern calendar (1572-1585) Noun
4. The Italian pope from 1406 to 1415 who worked to end the Great Schism and who retired to make it possible (1327-1417) Noun
5. The Italian pope who fought to establish the supremacy of the pope over the Roman Catholic Church and the supremacy of the church over the state (1020-1085) Noun
6. (Roman Catholic Church) an Italian pope distinguished for his spiritual and temporal leadership; a saint and Doctor of the Church (540?-604) Noun