Ethical (5)
![Ross](/clue/static/ross-mug.min.png)
I believe the answer is:
moral
'ethical' is the definition.
(synonyms)
This is all the clue.
(Other definitions for moral that I've seen before include "Concerned with principles of right and wrong" , "ethical standard" , "Relating to good and evil" , "Practical lesson to be drawn from an experience" , "Righteous" .)