co-father vs patriarch

co-father

noun
  • In a male homosexual couple, the nonbiological father (partner of the biological father) of a child. 

patriarch

noun
  • The male progenitor of a genetic or tribal line, or of a clan or extended family. 

  • A founder of a political or religious movement, an organization or an enterprise. 

  • The male head of a household or nuclear family. 

  • An old leader of a village or community. 

  • The highest form of bishop, in the ancient world having authority over other bishops in the province but now generally as an honorary title; in Roman Catholicism, considered a bishop second only to the Pope in rank. 

  • In Biblical contexts, a male leader of a family, tribe or ethnic group, especially one of the twelve sons of Jacob (considered to have created the twelve tribes of Israel) or (in plural) Abraham, Isaac and Jacob. 

How often have the words co-father and patriarch occurred in a corpus of books? (source: Google Ngram Viewer )