Old magistrate one's often seen with ruff (5)
I believe the answer is:
reeve
'old magistrate' is the definition.
(historical type of magistrate or judge)
'one's often seen with ruff' is the wordplay.
I cannot really understand how this works, but
'ruff' could be 'ree' (I have seen 'Female ruff ' mean 'ree' so perhaps 'ruff' could also mean 'ree') and 'ree' is found within the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for reeve that I've seen before include "See female bird" , "Saxon magistrate" , "Female ruff - Canterbury tale-teller" , "local official" , "magistrate of long ago" .)