Broken tablet causes fight (6)
I believe the answer is:
battle
'fight' is the definition.
(I know that fight can be written as battle)
'broken tablet' is the wordplay.
'broken' indicates anagramming the letters.
'tablet' is an anagram of 'BATTLE'.
'causes' acts as a link.
(Other definitions for battle that I've seen before include "Sussex town" , "Fight between armies" , "Fight between opponents" , "Warfare" , "Military fight" .)