The last word in prayers! (4)
I believe the answer is:
amen
'the last word' is the definition.
(last word in a prayer)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for amen that I've seen before include "Response to prayer" , "Extremist" , "as agreed!" , "So let it be" , "Prayerful last word" .)