Something used to fix broken plates (6)
I believe the answer is:
staple
'something used to fix' is the definition.
'broken plates' is the wordplay.
'broken' is an anagram indicator.
'plates' is an anagram of 'STAPLE'.
(Other definitions for staple that I've seen before include "Paper securer; main" , "Basic commodity and paper fastener" , "(Of food) necessary and important" , "Paper fastener - basic foodstuff" , "Main element" .)