What is Contentious Jurisdiction?

Legal Definition
In English ecclesiastical law, contentious jurisdiction (Latin: forum contentiosum) is jurisdiction over matters in controversy between parties, in contradistinction to voluntary jurisdiction, or that exercised upon matters not opposed or controverted.

The Lords Chief Justices, judges, etc., had a contentious jurisdiction; but, the Lords of the Treasury, the Commissioners of Customs, etc., have none, being merely judges of the accounts.
-- Wikipedia
Legal Definition
Eccl. law. In those cases where there is an action or judicial process, and it consists in hearing and determining the matter between party and party, it is said there is contentious jurisdiction, in contradistinction to voluntary jurisdiction, which is exercised in matters that require no judicial proceeding, as in taking probate of wills, granting letters of administration, and the like. 3 Bl. Com. 66.
-- Bouviers Law Dictionary
Legal Definition
In English ecclesiastical law. That branch of the jurisdiction of the ecclesiastical courts which is exercised upon adversary or contentious (opposed, litigated) proceedings.
-- Black's Law Dictionary
Legal Definition
Jurisdiction of causes between contending parties.
-- Ballentine's Law Dictionary