Moral

This entry's word is brought to you by Animaniacs. "Wheel of morality, turn, turn, turn. Tell us the lesson that we should learn."

The AHD defines the adjective moral as:

1. Of or concerned with the judgement of the goodness or badness of human action and character; ethical
2. Teaching or exhibiting goodness or correctness of character and behavior
3. Conforming to standards of what is right or just in behavior; virtuous
4. Arising from conscience sense or the sense of right and wrong

Looking at its origins, moral comes from the Latin moralis from mos, mor- meaning "custom". I really like the origin of this word because I feel that it provides a nice summary of what a moral actually is, a custom in a society concerning the definitions of right and wrong.