Mopes about in Surrey (5)
I believe the answer is:
epsom
'in surrey' is the definition.
(I've seen this before)
'mopes about' is the wordplay.
'about' indicates an anagram.
'mopes' anagrammed gives 'EPSOM'.
(Other definitions for epsom that I've seen before include "Mares would triumph here" , "Derby racecourse - salts" , "Home to the Derby and the Oaks" , "Surrey race course" , "Location of English Derby" .)