![pius xi pius xi](https://www.tekportal.net/wp-content/uploads/2018/11/pius-xi.jpg)
noun
- Achille Ratti, 1857–1939, Italian ecclesiastic: pope 1922–39.
noun
- original name Achille Ratti. 1857–1939, Italian ecclesiastic; pope (1922–39). He signed the Lateran Treaty (1929), by which the Vatican City was recognized as an independent state. His encyclicals condemned Nazism and Communism