Tablet smashed in Sussex town (6)
I believe the answer is:
battle
'sussex town' is the definition.
(I've seen this before)
'tablet smashed' is the wordplay.
'smashed' indicates an anagram.
'tablet' anagrammed gives 'BATTLE'.
'in' is the link.
(Other definitions for battle that I've seen before include "Naval engagement" , "Action" , "Conflict, fight" , "Fight between opposing forces" , "Wartime set piece" .)