Kind of joint that goes to the bishop's head (5)
I believe the answer is:
mitre
'kind of joint' is the definition.
(I know that mitre is a type of joint)
'goes to the bishop's head' is the wordplay.
I cannot really understand how this works, but
'the' could be 't' (the is pronounced as a 't' sound in some dialects) and 't' is located in the answer.
The remaining letters 'mire' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
'that' acts as a link.
Can you help me to learn more?
(Other definitions for mitre that I've seen before include "A bishop wears it" , "Episcopal headdress" , "bishop's head?" , "Bishop's headgear - joint" , "Item of headgear" .)