Cistercian (adj.) Look up Cistercian at Dictionary.com
c.1600, "pertaining to the Cistercian order of monks," with -an + Medieval Latin Cistercium (French Cîteaux), site of an abbey near Dijon, where the monastic order was founded 1098 by Robert of Molesme. As a noun, "monk of the Cistercian order," from 1610s.