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order [order 词源字典]: order: [13] Order comes via Old French ordre from Latin ōrdō. This originally denoted a ‘row, line, series, or other regular arrangement’, but it spawned a lot of other metaphorical meanings that have also come through into English, including ‘regularity’ and (from the general notion of a ‘rank’ or ‘class’) ‘ecclesiastical rank or office’ (preserved in English in ‘holy orders’ and in the derivatives ordain [13] and ordination [15]).

The sense ‘command, directive’, first recorded in English in the mid-16th century, presumably comes from the notion of ‘keeping in order’. Other derivatives of ōrdō are represented by ordinance [14] and ordinary.
=> ordain, ordinary, ordination[order etymology, order origin, 英语词源]
hagiarchy (n.): "government by persons in holy orders," 1826 (Southey, "Vindiciae Ecclesiae Anglicanae"); see hagio- "holy" + -archy. Not to be confused with hagiocracy "government by persons considered holy" (1816), with -cracy.
ordain (v.): late 13c., "to appoint or admit to the ministry of the Church," from stem of Old French ordener "place in order, arrange, prepare; consecrate, designate" (Modern French ordonner) and directly from Latin ordinare "put in order, arrange, dispose, appoint," from ordo (genitive ordinis) "order" (see order (n.)). The notion is "to confer holy orders upon." Meaning "to decree, enact" is from c. 1300; sense of "to set (something) that will continue in a certain order" is from early 14c. Related: Ordained; ordaining.
ordination (n.): early 15c., "the act of conferring holy orders," from Old French ordinacion (12c.) or directly from Latin ordinationem (nominative ordinatio) "a setting in order, ordinance," noun of action from past participle stem of ordinare "arrange" (see ordain).
proctor (n.): late 14c., contraction of procurator (c. 1300) "steward or manager of a household;" also "a provider" (see procurator). From late 14c. as "one who acts or speaks for another; spokesman, advocate;" early 15c. as "business manager or financial administrator of a church, college, holy order, etc."
sacrament (n.): "outward and visible sign of inward and spiritual grace," also "the eucharist," c. 1200, from Old French sacrament "consecration; mystery" (12c., Modern French sacrement) and directly from Latin sacramentum "a consecrating" (also source of Spanish sacramento, German Sakrament, etc.), from sacrare "to consecrate" (see sacred); a Church Latin loan-translation of Greek mysterion (see mystery).

Meaning "a holy mystery" in English is from late 14c. The seven sacraments are baptism, penance, confirmation, holy orders, the Eucharist, matrimony, and anointing of the sick (extreme unction).