Right skinny, by the sound of it (4)
I believe the answer is:
lien
'right' is the definition.
(legal right)
'skinny by the sound of it' is the wordplay.
'skinny' becomes 'lean' (similar in meaning).
'by the sound of it' indicates a 'sounds like' (homophone) clue.
'lean' is a homophone of 'LIEN'.
(Other definitions for lien that I've seen before include "Security for a debt" , "Legal claim on the property of another" , "The right to take property if an obligation is not discharged" , "Legal claim on Nile" , "Right to keep property" .)