knowing right from wrong (5)
I believe the answer is:
moral
'knowing right from wrong' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for moral that I've seen before include "Pertaining to right and wrong conduct" , "Behaving ethically" , "Virtuous and principled" , "Righteous" , "Relating to principles of right and wrong" .)