Sort of critic who bangs on the door? (7)
I believe the answer is:
knocker
'sort of critic' is the definition.
'knocker' can be an answer for 'critic' (I've seen this before). I am unsure of the 'sort of' bit.
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for knocker that I've seen before include "Hinged device on a door" , "Something on door; one continually finding fault" , "Door rapper" , "Alternative to door bell" , "means to announce house call" .)