Church Slavic, also known as Old Church Slavonic, is an ancient language that was used in liturgical and religious texts in the medieval Slavic world. Today, while the language is still used in certain Orthodox Christian communities, there are some alternative terms that are used to refer to it. Some of these synonyms include Old Bulgarian, Old Slavonic, and Old Macedonian. Additionally, in some contexts, the language may be referred to simply as Church Language or Church Writing. Despite the variations in terminology, Church Slavic remains a fascinating and important language with a rich history and heritage.