A profit one more time (5)
I believe the answer is:
again
'one more time' is the definition.
(I've seen this in another clue)
'a profit' is the wordplay.
'profit' becomes 'gain' (synonyms).
'a'+'gain'='AGAIN'
(Other definitions for again that I've seen before include "'Another time, once more (5)'" , "Moreover - a second time" , "On the other hand" , "Anew" , "Ocne more" .)