Billfold (6)
I believe the answer is:
wallet
'billfold' is the definition.
(I know that billfold can be written as wallet)
This is the entire clue.
(Other definitions for wallet that I've seen before include "A man's pocket-book" , "Notecase" , "Pocket case for money and documents" , "Small case for paper money" , "Pocket-sized money case" .)