Clue: Weston-super-Mare, such a mean place? (3-5,4)
Answer: ONE-HORSE TOWN
Explanation: Definition: such a mean place?

There is one mare (horse) in Weston-Super-Mare, so it could be described as a "one-horse town". Not sure why Vulcan has used the word "mean", as an average town would surely be big enough to have required more than one horse?