Reparation for a million closures (6)
I believe the answer is:
amends
'reparation' is the definition.
(both can mean making up for doing something wrong)
'a million closures' is the wordplay.
'million' becomes 'm' (abbreviation).
'closures' becomes 'ends' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'a'+'m'+'ends'='AMENDS'
'for' acts as a link.
Can you help me to learn more?
(Other definitions for amends that I've seen before include "It is made in reparation" , "Alters and improves" , "Alters, makes right" , "Corrects" , "Make these to right wrong" .)