The word originates from Avestan langauge as “Patar or Pitar“. It consists of two parts; “Pa” means “to watch” and the other part “Tar” shows a subjective suffix. On the whole, it signifies “someone who watches or protects”. In early Aryan times, Patar played a major role to watch or protect its family. In Sanskrit language, it is registered as “ पितृ (=PitR), too. In Pahlavi language, it is called “Pitar” or “Pit” and then entered into the modern Persian as “Pedar“. In the end, it is widely spread into other Aryan languages.
Some Aryan languages:
Pater in Latin
Father in English,
Père in French
Vater in German
Vader in Dutch
Far in Swedish, Danish and Norwegian
Pai in Portuguese
पिता (= pita) in Hindi
πατέρας(=patéras) in Greek