Perhaps equerry of dictator provides defence (8)
I believe the answer is:
palisade
'defence' is the definition.
(palisade is a kind of defence)
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for palisade that I've seen before include "fencing" , "Fence of stakes or iron railings" , "paling" , "Stockade" , "Protecting fence" .)