Cutting foot off grass is wrong (3)
I believe the answer is:
sin
'is wrong' is the definition.
(wrong can mean a sin or crime)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for sin that I've seen before include "Wrongdoing" , "Wickedness" , "Behave badly" , "Fall from grace" , "Err" .)