Professional salesman retired, as is right (6)
I believe the answer is:
proper
'is right' is the definition.
('proper' can be a synonym of 'right')
'professional salesman retired' is the wordplay.
'professional' becomes 'pro' ('pro' can be a synonym of 'professional').
'salesman' becomes 'rep' (I've seen this before).
'retired' says the letters should be written backwards.
'rep' backwards is 'per'.
'pro'+'per'='PROPER'
'as' is the link.
(Other definitions for proper that I've seen before include "Appropriate or decorous" , "Authentic" , "Appropriate description" , "name someone's given" , "Genuine; respectable" .)