'Watford' may mean the wet ford, or the ford used for hunting.
The ford crossed the River Colne, and the name was first recorded as Watforda in 1007. Watford's first station, built in 1836–7, stood north of St Albans Road. The larger Watford Junction station that replaced it in 1858 was built further south to take the new branch line to St Albans.