Religious congregation highly impatient after failing to be heard (9)
I believe the answer is:
synagogue
'religious congregation' is the definition.
(synagogue is a Jewish place of worship)
'highly impatient after failing to be heard' is the wordplay.
I cannot really see how this works, but
'impatient' could be 'agog' (I've seen this before) and 'agog' is present in the answer.
This may be the basis of clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for synagogue that I've seen before include "religious assembly" , "Jewish house of worship" , "Place for public Jewish worship" , "A building for public Jewish worship" , "Jewish temple" .)