Moderation (10)
'moderation' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for restraint that I've seen before include "Check" , "Self-discipline" , "Start rain as an impediment" , "It keeps someone or something under control" , "Moderation" .)
'moderation' is the definition.
(I know that moderation can be written as mitigation)
This is all the clue.
(Another definition for mitigation that I've seen is " Plea for mercy".)