The first Slavic literary language. Influenced development of modern Slavic languages, especially literary Russian. Used in liturgies of the Russian Orthodox Church and other Slavic churches. Found on https://irp.fas.org/world/russia/su_glos.html
(also known as Old Church Slavic) The first Slavic literary language, which influenced the development of the modern Slavic languages, including literary Russian. Used in liturgies of the Slavic Orthodox churches. After the twelfth century, known as Church Slavonic. Found on https://www.photius.com/countries/russia/glossary/index.html