A property may have one on it (4)
I believe the answer is:
lien
'a property may have one on it' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for lien that I've seen before include "Sequestration order" , "Legal claim on the property of another" , "Right to keep property" , "Legal right over the Nile" , "Legal claim on Nile" .)