Legal right (4)
I believe the answer is:
lien
'legal right' is the definition.
(legal term)
This is the entire clue.
(Other definitions for lien that I've seen before include "The right to take property if an obligation is not met" , "Right to retain property until a debt is paid" , "The right to take property if an obligation is not discharged" , "Legal right over the Nile" , "Security for a debt" .)