The title "Duke of Lancaster" has been held by members of the British royal family for centuries. However, there are several synonyms that can be used to refer to this important title. One of the most commonly used synonyms is "Earl of Lancaster," which is an older title that is still sometimes used today. Additionally, the term "Lancasterian" can be used to refer to someone associated with the county of Lancaster, which is where the original dukedom was located. Other synonyms for the Duke of Lancaster include "Lord of Bowland" and "Lord of Pendle." Each of these titles represents an important historical connection to the region that the Duke of Lancaster oversees.