1 ordinary

1: a (1) : a prelate exercising original jurisdiction over a specified territory or group (2) : a clergyman appointed formerly in England to attend condemned criminals
[M-W's Col. Dic.]

What purpose does the use of "original" serve in the above context? Please help me with it.

1: the power, right, or authority to interpret and apply the law
2 a : the authority of a sovereign power to govern or legislate b : the power or right to exercise authority : control
3: the limits or territory within which authority may be exercised
[M-W's Col. Dic.]
Original jurisdiction means that the ordinary (usually a bishop) makes decisions on all issues that come up in the region he has been given authority over. The issues may be appealed to a higher authority, but the bishop has the authority to deal with it first. This is similar to the legal distinction between a trial court and an appeals court. The trial courts have "original jurisdiction," that is, they make the first decision on cases that arise in their area. Only later, after a verdict has been given, can the case go to the appeals court.
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Thanks, Doc D.

Do the appellate courts also have an original jurisdictions, and does that jurisdition conincide with that of trial courts? Perhaps, that question should be asked of a lawyer.
You should probably ask a lawyer for the details. But, generally speaking, an appeals court has no original jurisdiction (it is not the first to make a verdict). As far as area goes, the appeals court oversees several trial courts. So its area is bigger. Oddly enough, the supreme court in some cases does have original jurisdiction (they decide some issues first).