Further American profit (5)
I believe the answer is:
again
'further' is the definition.
(thesaurus)
'american profit' is the wordplay.
'american' becomes 'a' (common abbreviation - e.g. in organisation names).
'profit' becomes 'gain' ('gain' can be a synonym of 'profit').
'a'+'gain'='AGAIN'
(Other definitions for again that I've seen before include "second term" , "Repeatedly" , "Predictably perhaps" , "repeat order" , "'Another time, once more (5)'" .)