Bring together Sun item's content (5)
I believe the answer is:
unite
'bring together' is the definition.
(I've seen this before)
'sun item's content' is the wordplay.
'content' indicates the answer is hidden within the clue (letters contained within the clue).
'UNITE' can be found hidden inside 'sun items'.
(Other definitions for unite that I've seen before include "Amalgamate" , "Pull together" , "Link" , "fuse" , "Put together" .)