Noun

Singular patriarch

Plural patriarchs

patriarch (plural patriarchs)

1. A male leader of a family, a tribe or an ethnic or religious group.
2. A founder of a political or religious movement, an organization or an enterprise.
3. Abraham, his son Isaac or his grandson Jacob. see Wikipedia
4. (Christianity) The highest form of bishop, generally in charge of an ethnic community, but in terms of the pope and the ecumenical patriarch, the former is the Patriarch of the West and the latter is the Patriarch of the East, a division dating to the Emperor Constantine the Great. The cities of Antioch, Alexandria, and almost as an afterthought, Jerusalem are accorded equal historical if not ecclesial dignity. Any and all other patriarchs, particularly that of the Russian church, are inferior.
5. (Bible Dictionary) Patriarch is an ordained office in the Melchizedek Priesthood. The fathers from Adam to Jacob were all patriarchs of this kind. The word as used in the Bible seems to denote also a title of honor to early leaders of the Israelites, such as David (Acts 2:29) and the 12 sons of Jacob (Acts 7:8-9). The word is of Greek derivation and means father-ruler; the Hebrew translation simply means father.

Originally a patriarch was a man who exercised autocratic authority as a pater familias over an extended family. The system of such rule of families by senior males is called patriarchy. This is a Greek word, a composition of πατήρ (pater) meaning "father" and ἄρχων (archon) meaning "leader", "chief", "ruler", "king", etc.

Abraham, Isaac, and Jacob are referred to as the three patriarchs of the people of Israel, and the period in which they lived is called the Patriarchal Age. It originally acquired its religious meaning in the Septuagint version of the Bible.

The word has mainly taken on specific ecclesiastical meanings. In particular, the highest-ranking bishops in Eastern Orthodoxy, Oriental Orthodoxy, the Roman Catholic Church (above Major Archbishop and primate), and the Assyrian Church of the East are called patriarchs. The office and ecclesiastical conscription (comprising one or more provinces, though outside his own (arch)diocese he is often without enforceable jurisdiction) of such a patriarch is called a patriarchate. Historically, a Patriarch may often be the logical choice to act as Ethnarch, representing the community that is identified with his religious confession within a state or empire of a different creed (as Christians within the Ottoman Empire).