From BiblePortal Wikipedia

Webster's Dictionary [1]

(n.) The spiritual head of the Armenian church, who resides at Etchmiadzin, Russia, and has ecclesiastical jurisdiction over, and consecrates the holy oil for, the Armenians of Russia, Turkey, and Persia, including the Patriarchs of Constantinople, Jerusalem, and Sis.

Cyclopedia of Biblical, Theological and Ecclesiastical Literature [2]

( Καθολικός ) ,

(1.) The title given, under Constantine, to his procurator, or vicar-general (after the organization of dioceses under imperial law), whose duty it was to see that all imperial rescripts were duly carried out. So in a letter from Constantine to Eusebius (preserved in Socrates, Hist.  Ecclesiastes 1:9), the emperor says: "Letters have been sent to the Διοικήσεως Καθολικόν , that he may provide all things necessary, etc. See Suicer, Thes. Ecclesiastes s.v.

(2.) The official title of certain of the Oriental prelates, especially of the patriarchs of the Armenian Church. He is appointed head of that part of the church over which his jurisdiction extends; he only can ordain bishops and consecrate the sacred oil. The dignity of Catholicos is inferior to that of patriarch, but superior to that of metropolitan. There are three dignitaries bearing the title in the Armenian Church at present the Catholicos of Etchmiadzin, the Catholicos of Aghtamar, the Catholicos of Sis. Coleman, Ancient Christianity, Ch. 27, § 2. (See Armenian Church).