Race meeting (5)
There are a few possibilities for this:
newmarket
(Other definitions for epsom that I've seen before include "Poems about English Derby venue" , "Poems about the race-course" , "Racetrack" , "place for racing" , "The Oaks and Derby are run here" .)
'race meeting' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for ascot that I've seen before include "course without any fences!" , "Royal race meeting venue" , "Horse-racing venue" , "Berkshire town, famous for horse racing" , "Royal Berkshire race-meeting (and fashion show!)" .)
(Other definitions for newmarket that I've seen before include "Suffolk town" , "Suffolk racecourse" , "horse-racing centre" , "course?" , "Betting card came" .)