What is "brading"

The ancient 'Kynges Towne' of Brading is the main town of the civil parish of the same name. The ecclesiastical parish of Brading used to cover about a tenth of the Isle of Wight. The current civil parish now includes the town itself and Adgestone, Morton, Nunwell and other outlying areas between Ryde, St Helens, Bembridge, Sandown and Arreton. Alverstone was transferred to the Newchurch parish some thirty years ago.