What is meant by "order" in reference to ministries within the Church, and how did its usage come about?

Question

FMS' answer to What are the positions relative to each other in the Catholic church's clerical hierarchy? mentioned a twofold hierarchy in the Church, that of order and that of jurisdiction.

Given examples from the secular world, it is a bit easier to understand what is meant by jurisdiction.

The question is, what is meant by order and how did its usage come about?

---

Note:

Please note @curiousdannii's comment that Anglicans also have a three fold order of ordination and a book called the Ordinal. Perhaps the answer will speak to the Anglican meaning so long doing so will not make this post off-topic.

Answer 1

"Order" comes from the Latin word "ordo", which can mean "rank", "class", "grade"—things of that sort. The Catechism, in its discussion of the Sacrament of Holy Orders, says:

The word order [sic, sc. ordo] in Roman antiquity designated an established civil body, especially a governing body. Ordinatio means incorporation into an ordo. In the Church there are established bodies which Tradition, not without a basis in Sacred Scripture, has since ancient times called taxeis (Greek) or ordines. And so the liturgy speaks of the ordo episcoporum, the ordo presbyterorum, the ordo diaconorum [respectively the "order of bishops", "order of priests", "order of deacons"]. Other groups also receive this name of ordo: catechumens, virgins, spouses, widows,....

Integration into one of these bodies in the Church was accomplished by a rite called ordinatio, a religious and liturgical act which was a consecration, a blessing or a sacrament. Today the word "ordination" is reserved for the sacramental act which integrates a man into the order of bishops, presbyters, or deacons, and goes beyond a simple election, designation, delegation, or institution by the community, for it confers a gift of the Holy Spirit that permits the exercise of a "sacred power" (sacra potestas) which can come only from Christ himself through his Church. Ordination is also called consecratio, for it is a setting apart and an investiture by Christ himself for his Church. The laying on of hands by the bishop, with the consecratory prayer, constitutes the visible sign of this ordination.

(Catechism of the Catholic Church, paragraphs 1537–38)

So an "order" generally speaking is simply one of the groups the Church recognizes as having a particular purpose or charism; and "order" in respect of the clerical hierarchy means one of the three groups set apart for the ministerial priesthood: bishops, priests, deacons.

Answer 2

I know nothing about usage of the word order (except that the ordaining process is a sacrament called Holy Orders), but I can address the first part of your question: what is meant by order (as opposed to jurisdiction)? The answer is that there is a hierarchy of functions or roles in the church's offices. Some offices allow the ordained person to do more than others. An acolyte (candle bearer) doesn't have much functionality, a deacon has quite a bit. It's like the army, where a general has more authority than a sergeant, and a sergeant in turn has more authority than a corporal, who in turn has more authority than a private. But at each step up the ladder of authority, you don't give up any of the power you previously had, you only take on additional responsibilities. Some of these functional differences arise out of divine mandates, others arise out of ecclesiastical discipline. Order deliberately says nothing about any territory you are responsible for, that's where jurisdiction comes in.

Jurisdiction applies only to the higher functions (orders) of offices (priests and bishops) because the lower offices don't have any territory associated with them. Territories are divided up into parishes as the smallest unit. These are grouped into deaneries, the deaneries are grouped into dioceses. Some dioceses are more important than others, so the lesser dioceses report to archdioceses. There may also be groups of dioceses corresponding to national levels or language usage. In the United States, the highest governing body is the USCCB (United States Conference of Catholic Bishops). In other countries there may be an individual archbishop, called a primate, in charge instead. Each of these levels of territory has a corresponding level of officeholder in the church hierarchy that is in charge of that territory. The highest jurisdictional office, is, of course, the pope who has universal jurisdiction. In terms of order, though, the pope is just a bishop. There is no order difference between an ordinary bishop, an archbishop, and the pope. The highest rank possible in terms of order is a bishop because he can do everything a priest can do, plus he can ordain priests and other bishops.