Cleric in the official list (5)
I believe the answer is:
canon
'cleric' is the definition.
(I've seen this before)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for canon that I've seen before include "Collection of writing" , "Member of a cathedral chapter" , "Principle - church dignitary - regulation" , "Criterion; church official" , "Big type" .)