This synonym for "to seclude" is also a word for part of a monastery or convent
... a place of religious 
seclusion: monastery or convent | monastic life | any place where one may lead a
... [DOC] [TLE] Cloister | Definition of Cloister by Merriam-Webster [PAR] Define cloister: a place where monks or nuns live : a monastery or convent ... 
later, English speakers began using the verb "cloister" to mean "to seclude in or 
as if in a cloister.