Stock carried by private landlord (9)
I believe the answer is:
innkeeper
'landlord' is the definition.
(I've seen this before)
'stock carried by private' is the wordplay.
'stock' becomes 'keep' (I've seen this before).
'carried by' is an insertion indicator.
'private' becomes 'inner' (as in one's private or inner thoughts).
'keep' inserted inside 'inner' is 'INNKEEPER'.
(Other definitions for innkeeper that I've seen before include "Manager who made extra provision for visitors" , "Pub licensee" , "Pub runner" , "Pub landlord" , "Mine host" .)