Keeper of a dog on a hill (7)
I believe the answer is:
curator
'keeper' is the definition.
(I know that keeper can be written as curator)
'a dog on a hill' is the wordplay.
'a dog' becomes 'cur' (both can mean a despicable person).
'on' is a charade indicator (letters next to each other).
'hill' becomes 'tor' (tor is a kind of hill).
'cur'+'a'+'tor'='CURATOR'
'of' acts as a link.
(Other definitions for curator that I've seen before include "Artistic director" , "Museum official" , "Custodian of a collection" , "Museum's administrative head" , "Keeper of a collection" .)