Cyrus /ˈsaɪərəs/ is the given name of a number of Persian kings. Most notably it refers to Cyrus the Great. Cyrus is also the name of Cyrus I of Anshan (ca. 650 BC), King of Persia the grandfather of Cyrus the Great; and Cyrus the Younger (died 401 BC), brother to the Persian King Artaxerxes II of Persia.
Cyrus, as a word in English, is the Latinized form of the Greek Κῦρος, Kȳros, from Old Persian