Headdress for the archbishop of Canterbury (5)
I believe the answer is:
mitre
'headdress for the archbishop of canterbury' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for mitre that I've seen before include "Sort of joint" , "Remit (anag.)" , "top?" , "that goes over a cleric's head?" , "Item of headgear" .)