Religious leader to witter on endlessly (5)
I believe the answer is:
rabbi
'religious leader' is the definition.
(Jewish religious leader)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for rabbi that I've seen before include "Hebrew scholar" , "Minister of a synagogue" , "Spiritual leader of a Jewish congregation" , "A Jewish priest" , "Legal expert" .)