Critic of door furniture (7)
I believe the answer is:
knocker
'critic' is the definition.
(I've seen this before)
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for knocker that I've seen before include "Front door feature" , "Critic" , "Door banger -- detractor" , "It bangs on a door" , "Hinged device on a door" .)