Religious leader's cut short talk (5)
I believe the answer is:
rabbi
'religious leader's' is the definition.
(Jewish religious leader)
'cut short talk' is the wordplay.
'cut short' means to remove the last letter.
'talk' becomes 'rabbit' (rabbit can informally mean to talk).
'rabbit' with its last letter taken away is 'RABBI'.
(Other definitions for rabbi that I've seen before include "Jewish religious teacher" , "Legal expert" , "Leader of worshippers" , "Hebrew scholar" , "A Jewish clergyman" .)