Reparation from that one mentioned (9)
I believe the answer is:
atonement
'reparation' is the definition.
(I've seen this before)
'from that one mentioned' is the wordplay.
'from' indicates a hidden word.
'ATONEMENT' can be found hidden inside 'that one mentioned'.
(Other definitions for atonement that I've seen before include "Compensation for a wrong" , "Expiation of sin, penance" , "reparations?" , "Reparation (for a wrong)" , "needed to make amends" .)