(From information collected, written and submitted by David Freeman at ): "Dewhurst is an English place name, from a so-named location in Lancashire, from the adjective "dewy" + the Middle English word "hyrst" = wooded hill. Dewhirst and Jewhurst are variations. The name Dewhurst comes from an area about six miles north of Blackburn, Lancashire, between Ribchester and Dinckley. The manor (meaning "area" not house) stretched both sides of the river Ribble and is recorded back as far as the fourteenth century.Some books refer to a small wood or "hurst" frequently engulfed in mist or "dew" hence people living in this area were known as living at or near dewey hurst. . . . The surname indicates simply "one from Dewhurst", a Lancashire toponym found near Blackburn. Indeed, the surname is common in Lancashire and the north of England in general. The name in fact derives from the Old English "deaw hyrst" and means "wet wood" or "damp wood", a feature near which the hamlet was located.
The surname is first documented in Lancashire in the early fourteenth century when one Roger de le Dewyhurst appears in the Coucher Book of Whalley Abby around the year 1300."