Prayer-ending word (4)
I believe the answer is:
amen
'prayer-ending word' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for amen that I've seen before include "statement of affirmation" , "Conclusion of prayer" , "Name for prayer's end" , "Religiously 11 [THE LASTWORD]" , "Word of approval" .)