More profit, America first (5)
I believe the answer is:
again
'more' is the definition.
(thesaurus)
'profit america first' is the wordplay.
'profit' becomes 'gain' (synonyms).
'america' becomes 'a' (common abbreviation - e.g. in organisation names).
'first' means one lot of letters go next to another.
'gain' after 'a' is 'AGAIN'.
(Other definitions for again that I've seen before include "Furthermore" , "return" , "One more time, encore" , "Moreover - a second time" , "Ocne more" .)