/ ˈwɒtfəd; NAmE ˈwɑːtfərd/ noun
( BrE ) a town in Hertfordshire, north of London, that is considered to mark the northern limit of the area of London and SE England. The expression north of Watford means the parts of Britain outside this area :
civil servants who seem to think the world ends north of Watford
For more information see the Cultural Guide