A profit? Another time! (5)
I believe the answer is:
again
'another time' is the definition.
(synonyms)
'a profit?' is the wordplay.
'profit?' becomes 'gain' ('gain' can be a synonym of 'profit').
'a'+'gain'='AGAIN'
(Other definitions for again that I've seen before include "return" , "Moreover - a second time" , "Furthermore" , "'Another time, once more (5)'" , "On the other hand" .)