Directory includes interminably boring compiler of religious scripts (9)
I believe the answer is:
liturgist
'compiler of religious scripts' is the definition.
The definition and answer can be both people as well as being singular nouns.
Perhaps there's a link between them I don't understand?
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for liturgist that I've seen before include "leader of service" , "service provider" , "Performer of ritual" .)