Character of landlord (6)
I believe the answer is:
letter
I believe this is a double definition.
'character' is the first definition.
(I know that letter is a type of character)
'landlord' is the second definition.
(landlords let property)
'of' acts as a link.
(Other definitions for letter that I've seen before include "An alphabetic unit" , "Eg, A" , "Written message" , "Written character - landlord" , "Form of correspondence" .)