The crossword solution for the term 'Trinity Writer' is URIS, which stands for the author Leon Uris. Uris was an American novelist and playwright who wrote many best-selling books such as Battle Cry, Exodus, Topaz, QB VII, Trinity, and The Haj. He was known for his vivid and detailed depictions of historical events, particularly the Jewish experience. His works often focused on themes of heroism, courage, and struggle.