Put right and couple up again (6)
I believe the answer is:
repair
'put right' is the definition.
(I've seen this before)
'couple up again' is the wordplay.
I cannot really see how this works, but
'couple' could be 'pair' (synonyms) and 'pair' is present in the answer.
'again' could be 're' (prefix meaning 'again') and 're' is found in the answer.
No letters remain.
This explanation may well be incorrect...
'and' is the link.
Can you help me to learn more?
(Other definitions for repair that I've seen before include "Make good again" , "Fix, mend" , "Patch up" , "Make one's way (to); fix" , "Withdraw" .)