Bulk of important record held by private landlord (9)
I believe the answer is:
innkeeper
'landlord' is the definition.
(I've seen this before)
'bulk of important record held by private' is the wordplay.
'bulk of important record' becomes 'keep' (I can't justify this - if you can you should believe this answer much more).
'held by' means one lot of letters goes inside another.
'private' becomes 'inner' (as in one's private or inner thoughts).
'keep' going inside 'inner' is 'INNKEEPER'.
Can you help me to learn more?
(Other definitions for innkeeper that I've seen before include "Mine host" , "Accommodating type" , "local manager" , "Pub landlord" , "Publican" .)