Encloister is a term that means to SECLUDE or isolate. It is derived from the Latin word 'claustrum' which means a closed space or enclosure. Encloister is often used to describe a place of retreat, such as a monastery or convent, where people can go to be away from the hustle and bustle of everyday life. It can also refer to the practice of isolating oneself from the world in order to focus on spiritual matters.