Meaning

noun residence that is a place of religious seclusion (such as a monastery)

noun a courtyard with covered walks (as in religious institutions)

verb surround with a cloister, as of a garden

originRecorded since about 1300 as Middle English cloistre, borrowed from Old French cloistre, clostre, or via Old English clauster, both from Medieval Latin claustrum (“portion of monastery closed off to laity”), from Latin claustrum (“place shut in, bar, bolt, enclosure”), a derivation of the past participle of claudere (“to close”). Doublet of claustrum.

Etymology from Wiktionary, CC BY-SA 3.0