patriarchal adj.

late 12c., patriarke, "one of the Old Testament fathers," progenitors of the Israelites, from Old French patriarche (11c.) and directly from Late Latin patriarcha (Tertullian), from Greek patriarkhēs "chief or head of a family," from patria "family, clan," from pater "father" (see father (n.)) + arkhein "to rule" (see archon). Also used as an honorific title of certain bishops of the highest rank in the early Church, notably those of Antioch, Alexandria, and Rome. The meaning "the father and ruler of a family" is by 1817.

suffix forming adjectives from nouns or other adjectives, "of, like, related to, pertaining to," Middle English -al, -el, from French or directly from Latin -alis (see -al (2)).