Make amends when in agreement (2,3)
I believe the answer is:
at one
'in agreement' is the definition.
(I've seen this before)
'make amends when' is the wordplay.
I cannot quite see how this works, but
'when' could be 'on' (I've seen this in other clues) and 'on' is present in the answer.
The remaining letters 'ate' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for at one that I've seen before include "Agreed" , "time to enjoy 21 and 15 [TURKEY and CRACKERS] s?" , "in harmony" , "In agreement" .)