Bankrupt agent? Not entirely (5)
I believe the answer is:
broke
'bankrupt' is the definition.
(thesaurus)
'agent? not entirely' is the wordplay.
'agent?' becomes 'broker' (synonyms).
'not entirely' means to remove the last letter (not all of the word).
'broker' with its final letter removed is 'BROKE'.
(Other definitions for broke that I've seen before include "Completely out of money" , "Shattered" , "Ordinal number" , "Impecunious" , "Lacking funds" .)