Creditor's security (4)
I believe the answer is:
lien
'creditor's security' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for lien that I've seen before include "Legal claim on Nile" , "Right to another's property, if an obligation is not discharged" , "The right to take property if an obligation is not met" , "Legal right to detain property" , "Right to keep property" .)