Anchorite:
A person under religious vows who generally does not leave his or her habitation. An anchorite lives enclosed in a room or cell, usually in very confined conditions. This kind of asceticism preceded organized monasticism. Simeon the Stylite, who lived on top of a pillar, was an anchorite. Julian of Norwich, an English mystic and anchoress, lived in a cell attached to her parish church in Norwich. See Hermit, Hermitess. [The Episcopal Church]
Noted in “Crypt review: Alice Roberts on murder and mayhem in the Middle Ages,” Michael Marshall, NewScientist (2 March 2024, paywall):
As [Crypt author Alice] Roberts explores the Middle Ages, she tackles the killing of Archbishop of Canterbury Thomas Becket, the sinking of the Mary Rose and the practice of walling oneself off inside a church to become an anchorite – in one story, a woman who may well have had syphilis walls herself off in a church in York. In her retelling, Roberts draws on a host of sources: not just the bones themselves, but historical documents, ethnography and anything else that is relevant.
A fascinating reminder that the tension between communalism vs. individualism, the latter of which is often taken to an extreme in American culture, can see human behaviors that are considered outré in one culture be common and significant in another.