Get back and once more go (6)
I believe the answer is:
return
'get back' is the definition.
(synonyms)
'once more go' is the wordplay.
'once more' becomes 're' (prefix in words like 're-emerge' or 're-enter').
'go' becomes 'turn' (as in one's go or turn in a game).
're'+'turn'='RETURN'
'and' is the link.
(Other definitions for return that I've seen before include "Give or come back" , "Come back; profit" , "Profit earned on money" , "Comeback" , "Retort" .)