Governor, a heartless Lombard (4)
I believe the answer is:
lord
'governor' is the definition.
The answer and definition can be both people as well as being singular nouns.
Perhaps they are linked in a way I don't understand?
'a heartless lombard' is the wordplay.
'a heartless' says to hollow out the word (remove centre letters).
'lombard' with its centre removed is 'LORD'.
Can you help me to learn more?
(Other definitions for lord that I've seen before include "Proprietor of a manor?" , "Man of noble rank" , "Titled nobleman" , "to be drunk?" , "Master, ruler or titled gent" .)