Place America in an advantage (4)
I believe the answer is:
plus
'an advantage' is the definition.
(thesaurus)
'place america' is the wordplay.
'place' becomes 'pl' (I've seen this in other clues).
'america' becomes 'us' (abbreviation for the United States).
'pl'+'us'='PLUS'
'in' acts as a link.
(Other definitions for plus that I've seen before include "To the French it's more" , "Add" , "An advantage (colloq.)" , "As well as" , "Advantage; also" .)