Property right patron drops outside of court (4)
I believe the answer is:
lien
'property right' is the definition.
(legal term)
I don't understand how the rest of the clue works.
(Other definitions for lien that I've seen before include "Security for a debt" , "Right to a lawyer" , "Sequestration order" , "The right to take property if an obligation is not met" , "Legal claim on Nile" .)