Principles or standards of behaviour (6)
I believe the answer is:
values
'principles or standards of behaviour' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for values that I've seen before include "Principles or standards of behaviour" , "Holds dear or regards highly" , "Appraises, assesses" , "Moral principles, standards" , "Considers to be of great worth or importance" .)