Tosca revitalised Berkshire town (5)
I believe the answer is:
ascot
'berkshire town' is the definition.
(town in Berkshire)
'tosca revitalised' is the wordplay.
'revitalised' indicates anagramming the letters.
'tosca' anagrammed gives 'ASCOT'.
(Other definitions for ascot that I've seen before include "Berkshire town, famous for horse racing" , "Place for meeting" , "English course" , "course without any fences!" , "Royal Berkshire race-meeting (and fashion show!)" .)