The charitable quarter (5)
I believe the answer is:
mercy
'quarter' is the definition.
(thesaurus)
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for mercy that I've seen before include "Compassion or forgiveness" , "'The quality of ... is not strained' (The Merchant of Venice)" , "Forbearance" , "Compassion for the unfortunate" , "Shakespeare 'The quality of . . . . . is not strained'" .)