The work doesn't really need us (4)
I believe the answer is:
opus
'the work' is the definition.
(an opus is an artistic work)
'doesn't really need us' is the wordplay.
'doesn't really' becomes 'op' (I can't explain this - if you can you should give a lot more credence to this answer).
'need' is a charade indicator (letters next to each other).
'op'+'us'='OPUS'
Can you help me to learn more?
(Other definitions for opus that I've seen before include "A Latin work" , "Composer's catalogue number" , "Composer's work" , "Creative work, eg in writing, art or music" , "Piece of music (with number)" .)