Animal ultimately out for synagogue official (5)
I believe the answer is:
rabbi
'synagogue official' is the definition.
(I've seen this in another clue)
'animal ultimately out' is the wordplay.
'animal' becomes 'rabbit' (I've seen this before).
'ultimately out' means to remove the last letter (the last or ultimate letter is taken out).
'rabbit' with its last letter taken off is 'RABBI'.
'for' acts as a link.
(Other definitions for rabbi that I've seen before include "legal scholar" , "Jewish learned man" , "Blue" , "A Jewish priest" , "Religious leader in a Jewish community" .)