I'd late amendment to item (6)
I believe the answer is:
detail
'to item' is the definition.
(synonyms)
'i'd late amendment' is the wordplay.
'amendment' indicates anagramming the letters.
'id'+'late'='idlate'
'idlate' is an anagram of 'DETAIL'.
(Other definitions for detail that I've seen before include "Factor" , "party" , "Small fact or feature" , "Small detachment of troops or police on special assignment" , "Small or important part" .)