/ˈklɔɪstər/
[noun] A covered walkway with arches on one side, built around a square garden in a monastery or convent; more broadly, a place or way of life that is quiet and separated from the outside world.
The word 'cloister' shares its ancient root with 'closet' and 'enclose' — all descending from a Latin word meaning 'to shut'.
The story of 'cloister' begins with the Latin verb claudere, meaning 'to shut' or 'to close'. This verb was one of the busiest roots in all of Latin, spawning dozens of descendants that spread across the languages of Europe. From claudere came the Latin noun claustrum, which meant a bolt, a bar, or any device used to lock something shut. A claustrum was, at its heart, a thing that kept the outside world out — and the inside world in.
As Latin evolved into the medieval spoken dialects of Europe, claustrum passed into Old French as cloistre, softening in sound and broadening in meaning. By the time it arrived in English during the 13th century — written as cloister — it referred specifically to the covered walkways built around the central garden of a monastery or convent. These architectural passages were designed for monks and nuns to walk, pray, and meditate while remaining sheltered from the weather, forming a kind of indoor-outdoor world that was neither fully public nor fully private.
The physical design of a cloister was itself an expression of its etymology. Enclosed on all sides, open only to the sky above the inner garden, a cloister was literally a shut-off space — a place where the noise and temptations of the secular world were locked away. The word carried this sense of deliberate separation from the very start, and over time it expanded from an architectural term to a spiritual and emotional one. To 'live in a cloister' came to mean not just inhabiting a physical building, but choosing a life of seclusion and contemplation.
Many of cloister's Latin relatives travelled into English through different routes, arriving in slightly different shapes. Latin claudere → Old French clore → English 'close'. Latin claustrum → Old French clos → English 'enclosure'. Latin claudere → Latin clausula → Old French clause → English 'clause'. Even the humble word 'closet' traces back through Old French closet, a diminutive of clos, to that same root of shutting and enclosing. The family is remarkably large, and its members pop up everywhere from legal documents to bedroom furniture.
In later centuries, the word took on a verb form as well. To 'cloister' someone came to mean to shut them away from the world — often protectively, sometimes oppressively. A young woman might be 'cloistered' by her family; a scholar might deliberately cloister himself in his library. This verbal use kept the original Latin energy alive: the sense that closing something off creates a special, separate reality, governed by different rules from the world outside. Today, 'cloistered' as an adjective still carries that slightly melancholy flavour — the image of someone who has been sheltered so completely that the ordinary world has become strange to them.