Hostile once more with good man (7)
I believe the answer is:
against
'hostile' is the definition.
(thesaurus)
'once more with good man' is the wordplay.
'once more' becomes 'again' (synonyms).
'with' is a charade indicator (letters next to each other).
'good man' becomes 'st' (abbreviation for saint).
'again'+'st'='AGAINST'
(Other definitions for against that I've seen before include "antagonistic" , "Not supporting" , "Facing" , "Not favouring" , "Disapproving of" .)