Intervening in desperate scrap, judge finally sums up (6)
I believe the answer is:
recaps
'sums up' is the definition.
(recapping is a kind of summing up)
'intervening in desperate scrap judge finally' is the wordplay.
'intervening in' is an insertion indicator.
'desperate' indicates an anagram (I've seen this in other clues).
'finally' suggests the final letters.
The last letter of 'judge' is 'e'.
'scrap' anagrammed gives 'rcaps'.
'rcaps' enclosing 'e' is 'RECAPS'.
(Other definitions for recaps that I've seen before include "Such summaries" , "Reviews" , "Summarises at the end" , "In brief, state again the main points" , "Summarises briefly" .)