"Couldn't agree more!" (4)

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amen

'couldn't agree more' 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 "Approve" , "Response to prayer" , "I agree!" , "Prayer ending" , "prayer's ending" .)

I've seen this clue in the Universal, the LA Times and The New York Times.

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