Be merciful towards (5)
I believe the answer is:
spare
(Other definitions for spare that I've seen before include "Pardon; unneeded" , "Don't use" , "Not required" , "Excess to requirements" , "With no excess fat" .)
I believe the answer is:
spare
(Other definitions for spare that I've seen before include "Pardon; unneeded" , "Don't use" , "Not required" , "Excess to requirements" , "With no excess fat" .)