Jack

Jack is an English given name that developed during the Middle Ages as a pet form of John, itself derived from the Hebrew Yohanan, meaning God is gracious. It became so widespread in medieval England that it was used as a general term for an ordinary man or boy, which is why it appears in countless folk sayings and nursery rhymes. The name has been borne by numerous notable figures, including several kings of England under its formal form John, as well as cultural icons in the modern era. Closely related forms include Jake, Jock, and the Latinate John, along with cognates such as Jan, Juan, and Jean across other languages.