Anush - From Zend anaosha (Parthian anosh) "immortal" later "pleasant", "sweet". This name was also used in Persia. It is also a constituent in a number of complex words (Haykanush, Vardanush, Hranush). It became popular due to H. Tumanyan's "Anush" opera. Petrosyan - Petrosyan, Petrosian or Petrossian (Eastern Armenian), Bedrosian or Bedrossian (Western Armenian) is a common surname in Armenia.
It is a patronymic from the Armenian first name Petros (equivalent to Peter).