Duke is the English word for a "nobleman" of the highest rank, from the Latin dux, "leader", and it has also been used as a nickname for Marmaduke. In the United States it carries the swagger of John Wayne, nicknamed The Duke, and of jazz legend Duke Ellington. Duke ranked number 1900 in 2000, entered the top 1000 in 2013 along with other title names like King and Royal, peaked at number 533 in 2018 and ranks number 695 in 2025.