roc n.

monstrous bird, rational and ancient, in Persian mythology, 1786 ("Vathek"), from Persian simurgh, from Pahlavi sin "eagle" + murgh "bird." Compare Avestan saeno merego "eagle," Sanskrit syenah "eagle," Armenian cin "kite." The thing is probably identical with the roc (q.v.).

[chess piece], c. 1300, roke, in chess, "one of the four pieces placed on the corners of the board," from Old French roc, Medieval Latin rocus, rochus, all from Arabic rukhkh, from Persian rukh, a name of unknown meaning, perhaps somehow related to the Indian name for the piece, rut, from Hindi rath "chariot." It was confused in Middle English with roc.