"Monasterial" is an adjective that usually describes something that is related to a monastery or a monk. Though not commonly used, there are various synonyms that can be used to describe something related to a monastery or monk. Some of the common synonyms are monastic, monastical, cloistered, conventual, and anchoritic. These words are often used when referring to a place or lifestyle that is associated with monks or monasteries such as "he joined the monastic order" or "she lived a cloistered life in the convent." Whether you're discussing history, religion or architecture, having a range of synonyms for a specific word is an advantageous knowledge for more effective and compelling communication.