Leniency (5)
I believe the answer is:
mercy
'leniency' is the definition.
(I know that mercy is a type of leniency)
This is all the clue.
(Other definitions for mercy that I've seen before include "Pity" , "Clemency or compassion" , "Shakespeare 'The quality of . . . . . is not strained'" , "Compassion for the unfortunate" , "Forbearance" .)