Lancaster Look up Lancaster at Dictionary.com
1086, Loncastre, literally "Roman Fort on the River Lune," a Celtic river name probably meaning "healthy, pure." In English history, the Lancastrians or House of Lancaster in the War of the Roses were the branch of the Plantagenets descended from John of Gaunt, Duke of Lancaster. Lancastrian (1828) is the usual adjective with places of that name; Lancasterian (1807) was used of the teaching methods popularized early 19c. by educator Joseph Lancaster (1778-1838).