Patriarch  n. 1 male head of a family or tribe. 2 (often in pl.)  Any of those regarded as fathers of the human race, esp. The sons of jacob, or abraham, isaac, and jacob, and their forefathers. 3 eccl. A chief bishop in the orthodox church. B rc ch. Bishop ranking immediately below the pope. 4 venerable old man.  patriarchal adj. [greek patria family, arkhes ruler]