Cis ‧ ter ‧ cian /səˈstɜːʃ ə n, sɪˈstɜːʃ ə n $ -ɜːr-/ BrE AmE noun
a ↑ monk (=member of an all-male Christian religious group) belonging to a group that started in France in 1098. The Cistercians follow the rules of St Benedict, which include little sleep, hard work, and not eating, but they do this even more strictly than the Benedictines.
—Cistercian adjective :
a Cistercian monastery