Once more without a profit (4)
I believe the answer is:
gain
'profit' is the definition.
(synonyms)
'once more without a' is the wordplay.
'once more' becomes 'again' (synonyms).
'without' indicates named letters should be taken away.
'again' with 'a' taken out is 'GAIN'.
(Other definitions for gain that I've seen before include "Advance" , "Win" , "Benefit; increase in value" , "Benefit; put on (weight)" , "Increase; secure" .)