communion (n.)youdaoicibaDictYouDict[communion 词源字典]
late 14c., from Old French comunion "community, communion" (12c.), from Latin communionem (nominative communio) "fellowship, mutual participation, a sharing," used in Late Latin ecclesiastical language for "participation in the sacrament," from communis (see common (adj.)). Used by Augustine, in belief that the word was derived from com- "with, together" + unus "oneness, union."[communion etymology, communion origin, 英语词源]